We’re shipping with new capabilities like detection for custom topics, and we're making AI endpoint discovery free for every Cloudflare customer—including those on Free, Pro, and Business plans—to give everyone visibility into where AI is deployed across their Internet-facing apps.

We're also announcing an expanded collaboration with IBM, which has chosen Cloudflare to deliver AI security to its cloud customers. And we’re partnering with Wiz to give mutual customers a unified view of their AI security posture.

Traditional web applications have defined operations: check a bank balance, make a transfer. You can write deterministic rules to secure those interactions. 

AI-powered applications and agents are different. They accept natural language and generate unpredictable responses. There's no fixed set of operations to allow or deny, because the inputs and outputs are probabilistic. Attackers can manipulate large language models to take unauthorized actions or leak sensitive data. Prompt injection, sensitive information disclosure, and unbounded consumption are just a few of the risks cataloged in the OWASP Top 10 for LLM Applications.

These risks escalate as AI applications become agents. When an AI gains access to tool calls—processing refunds, modifying accounts, providing discounts, or accessing customer data—a single malicious prompt becomes an immediate security incident.

Customers tell us what they’re up against. "Most of Newfold Digital's teams are putting in their own Generative AI safeguards, but everybody is innovating so quickly that there are inevitably going to be some gaps eventually,” says Rick Radinger, Principal Systems Architect at Newfold Digital, which operates Bluehost, HostGator, and Domain.com.

We built AI Security for Apps to address this. It sits in front of your AI-powered applications, whether you're using a third-party model or hosting your own, as part of Cloudflare's reverse proxy. It helps you (1) discover AI-powered apps across your web property, (2) detect malicious or off-policy behavior to those endpoints, and (3) mitigate threats via the familiar WAF rule builder.

Before you can protect your LLM-powered applications, you need to know where they're being used. We often hear from security teams who don’t have a complete picture of AI deployments across their apps, especially as the LLM market evolves and developers swap out models and providers. 

AI Security for Apps automatically identifies LLM-powered endpoints across your web properties, regardless of where they’re hosted or what the model is. Starting today, this capability is free for every Cloudflare customer, including Free, Pro, and Business plans. 

^{Cloudflare’s dashboard page of web assets, showing 2 example endpoints labelled as cf-llm}

Discovering these endpoints automatically requires more than matching common path patterns like /chat/completions. Many AI-powered applications don't have a chat interface: think product search, property valuation tools, or recommendation engines. We built a detection system that looks at how endpoints behave, not what they're called. To confidently identify AI-powered endpoints, sufficient valid traffic is required.

AI-powered endpoints that have been discovered will be visible under Security → Web Assets, labeled as cf-llm. For customers on a Free plan, endpoint discovery is initiated when you first navigate to the Discovery page. For customers on a paid plan, discovery occurs automatically in the background on a recurring basis. If your AI-powered endpoints have been discovered, you can review them immediately.

AI Security for Apps detections follow the always-on approach for traffic to your AI-powered endpoints. Each prompt is run through multiple detection modules for prompt injection, PII exposure, and sensitive or toxic topics. The results—whether the prompt was malicious or not—are attached as metadata you can use in custom WAF rules to enforce your policies. We are continuously exploring ways to leverage our global network, which sees traffic from roughly 20% of the web, to identify new attack patterns across millions of sites before they reach yours.

The product ships with built-in detection for common threats: prompt injections, PII extraction, and toxic topics. But every business has its own definition of what's off-limits. A financial services company might need to detect discussions of specific securities. A healthcare company might need to flag conversations that touch on patient data. A retailer might want to know when customers are asking about competitor products.

The new custom topics feature lets you define these categories. You specify the topic, we inspect the prompt and output a relevance score that you can use to log, block, or handle however you decide. Our goal is to build an extensible tool that flexes to your use cases.

^{Prompt relevance score inside of AI Security for Apps}

AI Security for Apps enforces guardrails before unsafe prompts can reach your infrastructure. To run detections accurately and provide real-time protection, we first need to identify the prompt within the request payload. Prompts can live anywhere in a request body, and different LLM providers structure their APIs differently. OpenAI and most providers use $.messages[*].content for chat completions. Anthropic's batch API nests prompts inside $.requests[*].params.messages[*].content. Your custom property valuation tool might use $.property_description.

Out of the box, we support the standard formats used by OpenAI, Anthropic, Google Gemini, Mistral, Cohere, xAI, DeepSeek, and others. When we can't match a known pattern, we apply a default-secure posture and run detection on the entire request body. This can introduce false positives when the payload contains fields that are sensitive but don't feed directly to an AI model, for example, a $.customer_name field alongside the actual prompt might trigger PII detection unnecessarily.

Soon, you'll be able to define your own JSONPath expressions to tell us exactly where to find the prompt. This will reduce false positives and lead to more accurate detections. We're also building a prompt-learning capability that will automatically adapt to your application's structure over time.

Once a threat is identified and scored, you can block it, log it, or deliver custom responses, using the same WAF rules engine you already use for the rest of your application security. The power of Cloudflare’s shared platform is that you can combine AI-specific signals with everything else we know about a request, represented by hundreds of fields available in the WAF. A prompt injection attempt is suspicious. A prompt injection attempt from an IP that’s been probing your login page, using a browser fingerprint associated with previous attacks, and rotating through a botnet is a different story. Point solutions that only see the AI layer can’t make these connections.

This unified security layer is exactly what they need at Newfold Digital to discover, label, and protect AI endpoints, says Radinger: “We look forward to using it across all these projects to serve as a fail-safe."

AI Security for Applications will also be available through Cloudflare's growing ecosystem, including through integration with IBM Cloud. Through IBM Cloud Internet Services (CIS), end users can already procure advanced application security solutions and manage them directly through their IBM Cloud account. 

We're also partnering with Wiz to connect AI Security for Applications with Wiz AI Security, giving mutual customers a unified view of their AI security posture, from model and agent discovery in the cloud to application-layer guardrails at the edge.

AI Security for Apps is available now for Cloudflare’s Enterprise customers. Contact your account team to get started, or see the product in action with a self-guided tour.

If you're on a Free, Pro, or Business plan, you can use AI endpoint discovery today. Log in to your dashboard and navigate to Security → Web Assets to see which endpoints we've identified. Keep an eye out — we plan to make all AI Security for Apps capabilities available for customers on all plans soon.

For configuration details, see our documentation.

For years, the industry’s answer to threats was “more visibility.” But more visibility without context is just more noise. For the modern security team, the biggest challenge is no longer a lack of data; it is the overwhelming surplus of it. Most security professionals start their day navigating a sea of dashboards, hunting through disparate logs to answer a single, deceptively simple question: "What now?"

When you are forced to pivot between different tools just to identify a single misconfiguration, you’re losing the window of opportunity to prevent an incident. That’s why we built a revamped Security Overview dashboard: a single interface designed to empower defenders, by moving from reactive monitoring to proactive control.

^{The new Security Overview dashboard.}

Historically, dashboards focused on showing you everything that was happening. But for a busy security analyst, the more important question is, "What do I need to fix right now?"

To solve this, we are introducing Security Action Items. This feature acts as a functional bridge between detection and investigation, surfacing vulnerabilities, so you no longer have to hunt for them. To help you triage effectively, items are ranked by criticality:

• Critical: Urgent risks requiring immediate attention to prevent exploitation.

• Moderate: Issues that should be addressed to maintain a strong security posture.

• Low: Best-practice optimizations and hardening suggestions.

By filtering by Insight Type (such as Suspicious Activity or Insecure Configuration), you can tailor your workflow to the specific threats your organization faces most.

One of the most common causes of a breach isn't the absence of a security tool, it’s the fact that the tool was never turned on or was configured incorrectly. We call this the configuration gap.

The new Detection Tools module eliminates this blind spot. Instead of digging through nested settings pages to see if your traffic is actually being inspected, we provide a high-level status of your entire Cloudflare security stack in one view:

• Are your primary shields active, or are you in "Log Only" mode during a period of increased volatility? 

• Are you discovering shadow APIs, or are you flying blind?

By surfacing these tools directly alongside your Security Action Items, we move the conversation from "Do we have this tool?" to "Is this tool actively protecting us right now?"

A high-level summary is only as good as the data behind it. To make the transition from a red flag to a solution seamless, we have unified the visibility of our Suspicious Activity cards. These cards now live in two strategic places: the Security Overview and the Security Analytics page.

If you spot a Suspicious Activity card on your Overview page that piques your interest, there is no need to manually navigate to Analytics and re-create your filters. By clicking on the card, you are deep-linked directly into the Security Analytics dashboard with all the relevant filters automatically applied. This eliminates the "tab switching tax" that slows down incident response, keeping your workflow fluid and your response times fast.

To maintain a proactive defense, our engine produces and refreshes over 10 million actionable insights every day to ensure protection is always current.

Operating at this level presents two distinct engineering challenges. The first is scale: processing massive volumes of data seamlessly. The second and arguably harder challenge, is breadth. True security is horizontal, spanning your entire stack. To generate actionable insights that give you a comprehensive view of your risks and vulnerabilities, our engine must validate everything from simple SSL certificates to complex AI bot configurations.

To solve this, we built a system composed of smaller, specialized micro services, which we call checkers. Each checker is a subject-matter expert for a specific part of your stack, such as DNS records. The distribution of our checkers allows them to scale independently, hooked into the system in two ways: scheduled configuration checks or real-time listeners that flag a risk the instant an event occurs.

1. Scheduled checks: We deploy this mode for risks that need deep inspection. These are triggered by an orchestrator (scheduler), which periodically pushes tasks for the checkers to execute. We distribute the checker workload across a massively parallel system. For example, a task sent to the DNS checker might be: "Scan all the DNS related configurations of zone xyz.com and find anomalies."

The checkers pick up these tasks independently. They use their specialized intelligence to scan through the assets and configurations. In the case of the DNS checker, it uses specialized and intelligent rules to scan all the DNS assets and configurations of a zone, be it A/AAAA/CNAME records or DMARC or SPF records. 

This is what the insight lifecycle looks like: 

1. The checker activates when a message is received. 

2. The checker collects relevant assets (e.g., DNS records) about the zone or account.

3. The checker runs several checks to verify the status of the asset, e.g., if a CNAME record points to a server.

4. If the state or configuration doesn’t meet the required threshold, an insight is flagged.

5. During the next check, if the insight persists, the timestamp is updated.

6. If the insight has been remedied during the next check, it will be removed from the database.

2. Event handlers: The checkers operate on a schedule round the clock, whereas the event handlers function in real-time. They listen to signals and events from our control plane.

This is what the real-time ruleset insight lifecycle looks like:

1. A WAF rule configuration is modified.

2. An event containing details of the change is triggered immediately.

3. The ruleset handler, which is actively listening, kicks into action.

4. The handler detects an anomaly, e.g, you have enabled the Cloudflare Managed Ruleset but left it in "Log Only" mode.

5. The handler deduces that the attacks are being recorded but not blocked.

6. The handler registers an insight and makes it available on the dashboard.

7. If the configuration has been updated to a secure setting, the handler clears the insight.

The real-time nature of Ruleset handlers allow us to flag a misconfiguration or confirm a fix instantly.

Our customers have consistently asked for more than just visibility: they’ve asked for context. While a notification that a record is misconfigured is helpful, it’s only half the story. To take immediate, confident action, defenders need to know the "so what?" including the business impact and the technical root cause. To address this, we have developed Contextual Insights for our detection engine. By surfacing data like traffic volume to a broken A record, we ensure that every insight is an invitation to act.

We are starting this journey of Contextual Insights by expanding the depth of our DNS insights. Instead of just flagging a broken record, we correlate the dangling signal with additional context and real-time traffic data to provide the “why” and the “how”:

• Target Context: We identify exactly which deleted resource (e.g., an old S3 bucket or cloud instance) the record points to.

• Impact Context: We show you exactly how many users are still trying to reach that broken record.

Let’s explore the ‘Dangling A/AAAA/CNAME record’ insights as an example. 

To provide these insights, we must analyze the massive amount of data flowing through our network every second. To give you an idea of the work happening behind the scenes:

100+ million DNS records are scanned weekly by our engine. In the past week, our engine identified over 1 million dangling DNS records. The majority (97%) are Dangling A/AAAA records and the remaining 3% are Dangling CNAME records.

Of the 31,000 dangling CNAME records:

• 95% point to Microsoft Azure services.

• 3% point to AWS Elastic Beanstalk.

This signals that these are high-priority targets for a subdomain takeover. An attacker can claim these abandoned cloud resources and immediately control your subdomain, allowing them to launch phishing attacks or spread misinformation under your trusted brand. With thousands of hits, a dangling record presents a high-priority risk for a subdomain takeover, necessitating immediate remediation to instantly gauge and mitigate the threat.

Our DNS checker uses a two-step process to generate these insights

• Step 1: Active Insight detection

  • The checker starts verification as soon as it gets the message to start a scan. This process has been described in an earlier section.

• Step 2: Contextual enrichment

  • Once the insight is generated, the checkers gather relevant contextual data for the insight that helps the customer in understanding the impact of the security insight.

Let’s explore in depth how the dangling DNS record insights are generated, focusing on the two-phase process involved. 

A DNS record pointing to an IP address often looks perfectly valid on paper, even if the server behind it was decommissioned months ago. To confirm if a risk is real, our engine has to step outside the network and probe the destination in real-time. The checks performed can be categorized as follows:

The dead server check (A/AAAA records): For records pointing directly to IP addresses, we verify if the destination is still active. Our engine spins up a dedicated egress proxy to attempt a connection to the origin over HTTP and HTTPS. By using this special gateway, we simulate how a real user would connect from outside Cloudflare’s network. If the connection times out or the server returns a "404 Not Found" error, we confirm the resource is dead. This proves the DNS record is "dangling", a live signpost pointing to an empty lot.

The takeover check (CNAME records): Domain aliases (CNAMEs) often delegate traffic to third-party services, like a helpdesk or storage bucket. If you cancel that service but forget to delete the DNS record, you create a "dangling" link that attackers can claim.

To find these, our engine performs a 3-step process:

1. First, we trace the chain by recursively resolving the CNAME record to find its final destination (e.g., my-bucket.s3.amazonaws.com).

2. Next, we identify the provider by checking if that destination belongs to a known cloud service like AWS, Azure, or Shopify.

3. Finally, we confirm vacancy. Each cloud provider returns specific error patterns when a resource doesn't exist  (e.g., S3's "NoSuchBucket"). We probe the destination URL and match against these patterns to confirm if the resource is claimable.

If our engine detects that a resource has been released but the DNS record remains, we create an insight, prompting you to remove the record before an attacker can take over your subdomain. 

Once a record is verified as broken, we add the necessary context to the insight that helps you take better action. The checker connects to different systems to gather the required context. For dangling insights, we focus on three critical dimensions:

• Traffic Volume (The Impact) Our global ClickHouse clusters are a treasure trove of information. To understand if the record is actually in use, the checker queries our global ClickHouse clusters to sum up the total DNS queries for that record over the last 7 days. This valuable context lets you prioritize the remedy. A record with 0 queries can be fixed when you have time; a record with 10,000 queries is an active vulnerability that needs to be patched immediately.

Query to the clickhouse looks like: 

SELECT query_name,
       sum(_sample_interval) as total
  FROM <dnslogs_table_name>
 WHERE account_id = {{account_id}}
   AND zone_id = {{zone_id}}
   AND timestamp >= subtractDays(today(), 7)
   AND timestamp < today()
   AND query_name in ('{{record1}}', '{{record2}}', ...)
 GROUP BY query_name

The query asks “How many times has this specific broken record been requested by real users in the last seven days?”

• Infrastructure owner (The Target) Knowing who owns the destination infrastructure is    vital for both remediation and severity assessment. 

For IP records (A/AAAA): We identify the network owner (ASN) through the latest geolocation data from a Cloudflare R2 bucket and performing high-speed lookups in memory. It tells you exactly where the dead resource lived (e.g., "Google Cloud" vs. "DigitalOcean"), speeding up your investigation. 

For CNAME Records: We identify the specific Hosting Provider (e.g., AWS S3, Shopify). This dictates the risk level. If a record points to a provider known for easy takeovers (like S3), we mark it as Critical; otherwise, it is Moderate.

• DNS TTL We also extract the TTL (Time To Live) value directly from the record configuration.

This tells you the "lag time" of your fix. If you delete a dangling record with a high TTL (e.g., 24 hours), it will remain cached in resolvers around the world for a full day, meaning the vulnerability stays open even after you patch it. Knowing this helps you manage expectations during an incident response.

While this experience is launching at the domain level today, we know that for enterprise customers, security isn't managed just one domain at a time. Our roadmap is focused on bringing this intelligence to the account level next. Soon, security teams can use a centralized view that aggregates security action items and prioritizes the most critical risks to remediate across all of their Cloudflare domains.

Security shouldn't feel like a game of catch-up. For too long, the complexity of managing application security has given the advantage to the attacker. Through our architecture of specialized checkers and real-time event handlers, we detect potential risks and enrich them with critical context, ensuring defenders can respond with speed and precision.

The new Security Overview is now the starting point for your day, a place where risk data is transformed into a prioritized strategy. Log in to the Cloudflare dashboard today to explore your new Application Security Overview page!

Replacing manual, point-in-time audits with automated security posture visibility is critical to growing your Internet presence safely. That’s why we are happy to announce a planned integration that will enable the continuous discovery, monitoring and remediation of Internet-facing blind spots directly in the Cloudflare dashboard: Mastercard’s RiskRecon attack surface intelligence capabilities.

Information Security practitioners in pay-as-you-go and Enterprise accounts will be able to preview the integration in the third quarter of 2026.

Mastercard’s RiskRecon attack surface intelligence identifies and prioritizes external vulnerabilities by mapping an organization's entire internet footprint using only publicly accessible data. As an outside-in scanner, the solution can be deployed instantly to uncover "shadow IT," forgotten subdomains, and unauthorized cloud servers that internal, credentialed scans often miss. By seeing what an attacker sees in real time, security teams can proactively close security gaps before they can be exploited.

But what security gaps are attackers typically looking to exploit? In a 2025 study of 15,896 organizations that had experienced security breaches, Mastercard found that unpatched software, exposed services (e.g. databases, remote administration), weak application security (e.g. missing authentication) and outdated web encryption were frequent hallmarks, as seen in the graph below.

The same study also found that organizations with significant cybersecurity posture gaps in these areas were 5.3x more likely to be hit by a ransomware attack, and 3.6x more likely to suffer a data breach compared to companies that maintain good cybersecurity hygiene.

This partnership combines Mastercard’s attack surface intelligence—which identifies security gaps—with Cloudflare’s ability to fix them. Organizations can use Mastercard’s data to find shadow assets, such as forgotten domains or unprotected cloud instances, and secure them by routing traffic through Cloudflare’s proxy. This allows for the immediate deployment of security controls without changing the underlying website or application.

Based on a sample of approximately 388,000 organizations spanning over 18 million systems, Mastercard’s attack surface intelligence shows that systems using Cloudflare as a proxy have significantly better security hygiene than those that do not:

• Software Patching: 53% fewer software vulnerabilities

• Web Encryption: 58% fewer SSL/TLS issues

• System Reputation: 98% fewer instances of malicious behavior (e.g. communicating with botnet command and control servers, hosting phishing sites).

The table below provides additional details on the security posture insights provided by Mastercard. These insights are generated by passively scanning publicly accessible hosts, web applications, and configurations. 

Cloudflare Security Insights in Cloudflare’s Application Security suite currently identifies risks—such as DNS misconfigurations, weak web encryption, or inactive WAF rules—for any domain already proxied by Cloudflare. However, a significant security gap remains: you cannot protect domains you don’t know exist.

The integration with Mastercard will eliminate these blind spots. By continuously profiling the Internet footprint of over 12 million organizations, Mastercard identifies domains, hosts, and software stacks associated with your company, even if they aren't yet behind a Cloudflare proxy. This will allow Security Insights to surface shadow IT and unprotected hosts, enabling you to secure them with Cloudflare’s WAF and DDoS protection. 

Visibility is only the first step; understanding the criticality of discovered assets is what allows security teams to prioritize findings. Each host is assigned a criticality level:

• High Criticality: Assigned to hosts that collect sensitive data, require authentication, or run sensitive network services like database listeners or remote access.

• Medium Criticality: Assigned to hosts running brochure websites that are adjacent to high-criticality systems, such as those residing on the same class-C network.

• Low Criticality: Assigned to hosts running brochure websites that are not adjacent to any critical systems.

Below is a fictitious example of an organization with many domains that they are unaware of. Of these discovered domains, only one is currently proxied by Cloudflare. Within Security Insights, you will be able to visualize this level of detail for shadow domains and hosts. 

^{Example of shadow domains and unprotected hosts associated with an organization}

Mastercard will also allow continuous visibility into the security posture of Internet-facing systems including in areas like software patching, exposed network services (e.g., databases, remote access) and application security (e.g., unauthenticated CMSes) — complementing Cloudflare Security Insights, as shown below.

^{Security Insights dashboard with shadow domains, unproxied hosts, and posture findings}

These insights are only useful if they lead to action. Instead of just telling you that a domain or host is at risk, Cloudflare Security Insights will guide you to fixing them. Possible steps include enabling a Cloudflare proxy (and by extension DDoS and bot protection for shadow zones and hosts), enabling security controls (such as turning on the Web Application Firewall, or WAF) and enforcing stricter TLS encryption to mitigate the specific risks identified by the scan.

We are currently working on integrating Mastercard’s RiskRecon attack surface intelligence into the Cloudflare Security Insights dashboard to provide immediate visibility into shadow domains, unprotected hosts and the posture gaps associated with them.

With an increasing volume of insights, our roadmap also includes risk scoring and building AI-assisted diagnosis paths. That will mean a dashboard that doesn't just show you an insight, but proposes additional relevant correlations (such as traffic to an unpatched host) and suggests the specific WAF rule or API Shield configuration required to neutralize it.

We would love to have you join the waitlist here.

The vulnerabilities are CVE-2026-2833, CVE-2026-2835, and CVE-2026-2836. These issues were responsibly reported to us by Rajat Raghav (xclow3n) through our Bug Bounty Program.

Cloudflare’s CDN and customer traffic were not affected, our investigation found. No action is needed for Cloudflare customers, and no impact was detected. 

Due to the architecture of Cloudflare’s network, these vulnerabilities could not be exploited: Pingora is not used as an ingress proxy in Cloudflare’s CDN.

However, these issues impact standalone Pingora deployments exposed to the Internet, and may enable an attacker to:

• Bypass Pingora proxy-layer security controls

• Desync HTTP request/responses with backends for cross-user hijacking attacks (session or credential theft)

• Poison Pingora proxy-layer caches retrieving content from shared backends

We have released Pingora 0.8.0 with fixes and hardening. While Cloudflare customers were not affected, we strongly recommend users of the Pingora framework to upgrade as soon as possible.

The reports described a few different HTTP/1 attack payloads that could cause desync attacks. Such requests could cause the proxy and backend to disagree about where the request body ends, allowing a second request to be “smuggled” past proxy‑layer checks. The researcher provided a proof-of-concept to validate how a basic Pingora reverse proxy misinterpreted request body lengths and forwarded those requests to server backends such as Node/Express or uvicorn.

Upon receiving the reports, our engineering team immediately investigated and validated that, as the reporter also confirmed, the Cloudflare CDN itself was not vulnerable. However, the team did also validate that vulnerabilities exist when Pingora acts as the ingress proxy to shared backends.

By design, the Pingora framework does allow edge case HTTP requests or responses that are not strictly RFC compliant, because we must accept this sort of traffic for customers with legacy HTTP stacks. But this leniency has limits to avoid exposing Cloudflare itself to vulnerabilities.

In this case, Pingora had non-RFC-compliant interpretations of request bodies within its HTTP/1 stack that allowed these desync attacks to exist. Pingora deployments within Cloudflare are not directly exposed to ingress traffic, and we found that production traffic that arrived at Pingora services were not subject to these misinterpretations. Thus, the attacks were not exploitable on Cloudflare traffic itself, unlike a previous Pingora smuggling vulnerability disclosed in May 2025.

We’ll explain, case-by-case, how these attack payloads worked.

The first report showed that a request with an Upgrade header value would cause Pingora to pass through subsequent bytes on the HTTP connection immediately, before the backend had accepted an upgrade (by returning 101 Switching Protocols). The attacker could thus pipeline a second HTTP request after the upgrade request on the same connection:

GET / HTTP/1.1
Host: example.com
Upgrade: foo


GET /admin HTTP/1.1
Host: example.com

Pingora would parse only the initial request, then treat the remaining buffered bytes as the “upgraded” stream and forward them directly to the backend in a “passthrough” mode due to the Upgrade header (until the response was received).

This is not at all how the HTTP/1.1 Upgrade process per RFC 9110 is intended to work. The subsequent bytes should only be interpreted as part of an upgraded stream if a 101 Switching Protocols header is received, and if a 200 OK response is received instead, the subsequent bytes should continue to be interpreted as HTTP.

^{An attacker that sends an Upgrade request, then pipelines a partial HTTP request may cause a desync attack. Pingora will incorrectly interpret both as the same upgraded request, even if the backend server declines the upgrade with a 200.}

Via the improper pass-through, a Pingora deployment that received a non-101 response could still forward the second partial HTTP request to the upstream as-is, bypassing any Pingora user‑defined ACL-handling or WAF logic, and poison the connection to the upstream so that a subsequent request from a different user could improperly receive the /admin response.

^{After the attack payload, Pingora and the backend server are now “desynced.” The backend server will wait until it thinks the rest of the partial /attack request header that Pingora forwarded is complete. When Pingora forwards a different user’s request, the two headers are combined from the backend server’s perspective, and the attacker has now poisoned the other user’s response.}

We’ve since patched Pingora to switch the interpretation of subsequent bytes only once the upstream responds with 101 Switching Protocols.

We verified Cloudflare was not affected for two reasons:

1. The ingress CDN proxies do not have this improper behavior.

2. The clients to our internal Pingora services do not attempt to pipeline HTTP/1 requests. Furthermore, the Pingora service these clients talk directly with disables keep-alive on these Upgrade requests by injecting a Connection: close header; this prevents additional requests that would be sent — and subsequently smuggled — over the same connection.

The reporter also demonstrated what appeared to be a more classic “CL.TE” desync-type attack, where the Pingora proxy would use Content-Length as framing while the backend would use Transfer-Encoding as framing:

GET / HTTP/1.0
Host: example.com
Connection: keep-alive
Transfer-Encoding: identity, chunked
Content-Length: 29

0

GET /admin HTTP/1.1
X:

In the reporter’s example, Pingora would treat all subsequent bytes after the first GET / request header as part of that request’s body, but the node.js backend server would interpret the body as chunked and ending at the zero-length chunk. There are actually a few things going on here:

1. Pingora’s chunked encoding recognition was quite barebones (only checking for whether Transfer-Encoding was “chunked”) and assumed that there could only be one encoding or Transfer-Encoding header. But the RFC only mandates that the final encoding must be chunked to apply chunked framing. So per RFC, this request should have a chunked message body (if it were not HTTP/1.0 — more on that below).

2. Pingora was also not actually using the Content-Length (because the Transfer-Encoding overrode the Content-Length per RFC). Because of the unrecognized Transfer-Encoding and the HTTP/1.0 version, the request body was instead treated as close-delimited (which means that the response body’s end is marked by closure of the underlying transport connection). An absence of framing headers would also trigger the same misinterpretation on HTTP/1.0. Although response bodies are allowed to be close-delimited, request bodies are never close-delimited. In fact, this clarification is now explicitly called out as a separate note in RFC 9112.

3. This is an HTTP/1.0 request that did not define Transfer-Encoding. The RFC mandates that HTTP/1.0 requests containing Transfer-Encoding must “treat the message as if the framing is faulty” and close the connection. Parsers such as the ones in nginx and hyper just reject these requests to avoid ambiguous framing.

^{When an attacker pipelines a partial HTTP request header after the HTTP/1.0 + Transfer-Encoding request, Pingora would incorrectly interpret that partial header as part of the same request, rather than as a distinct request. This enables the same kind of desync attack as described in the premature Upgrade example.}

This spoke to a more fundamental misreading of the RFC particularly in terms of response vs. request message framing. We’ve since fixed the improper multiple Transfer-Encoding parsing, adhere strictly to the request length guidelines such that HTTP request bodies can never be considered close-delimited, and reject invalid Content-Length and HTTP/1.0 + Transfer-Encoding request messages. Further protections we’ve added include rejecting CONNECT requests by default because the HTTP proxy logic doesn’t currently treat CONNECT as special for the purposes of CONNECT upgrade proxying, and these requests have special message framing rules. (Note that incoming CONNECT requests are rejected by the Cloudflare CDN.)

When we investigated and instrumented our services internally, we found no requests arriving at our Pingora services that would have been misinterpreted. We found that downstream proxy layers in the CDN would forward as HTTP/1.1 only, reject ambiguous framing such as invalid Content-Length, and only forward a single Transfer-Encoding: chunked header for chunked requests.

The researcher also reported one other cache poisoning vulnerability regarding default CacheKey construction. The naive default implementation factored in only the URI path (without other factors such as host header or upstream server HTTP scheme), which meant different hosts using the same HTTP path could collide and poison each other’s cache.

This would affect users of the alpha proxy caching feature who chose to use the default CacheKey implementation. We have since removed that default, because while using something like HTTP scheme + host + URI makes sense for many applications, we want users to be careful when constructing their cache keys for themselves. If their proxy logic will conditionally adjust the URI or method on the upstream request, for example, that logic likely also must be factored into the cache key scheme to avoid poisoning.

Internally, Cloudflare’s default cache key uses a number of factors to prevent cache key poisoning, and never made use of the previously provided default.

If you use Pingora as a proxy, upgrade to Pingora 0.8.0 at your earliest convenience.

We apologize for the impact this vulnerability may have had on Pingora users. As Pingora earns its place as critical Internet infrastructure beyond Cloudflare, we believe it’s important for the framework to promote use of strict RFC compliance by default and will continue this effort. Very few users of the framework should have to deal with the same “wild Internet” that Cloudflare does. Our intention is that stricter adherence to the latest RFC standards by default will harden security for Pingora users and move the Internet as a whole toward best practices.

- 2025‑12‑02: Upgrade‑based smuggling reported via bug bounty.

- 2026‑01‑13: Transfer‑Encoding / HTTP/1.0 parsing issues reported.

- 2026-01-18: Default cache key construction issue reported.

- 2026‑01‑29 to 2026‑02‑13: Fixes validated with the reporter. Work on more RFC-compliance checks continues.

- 2026-02-25: Cache key default removal and additional RFC checks validated with researcher.

- 2026‑03-02: Pingora 0.8.0 released.

- 2026-03-04: CVE advisories published.

We thank Rajat Raghav (xclow3n) for the report, detailed reproductions, and verification of the fixes through our bug bounty program. Please see the researcher's corresponding blog post for more information.

We would also extend a heartfelt thank you to the Pingora open source community for their active engagement, issue reports, and contributions to the framework. You truly help us build a better Internet.

That’s why today, we are launching the beta of Cloudflare’s Web and API Vulnerability Scanner. 

We are starting with the most pervasive and difficult-to-catch threat on the OWASP API Top 10: Broken Object Level Authorization, or BOLA. We will add more vulnerability scan types over time, including both API and web application threats.

The most dangerous API vulnerabilities today aren’t generic injection attacks or malformed requests that a WAF can easily spot. They are logic flaws—perfectly valid HTTP requests that meet the protocol and application spec but defy the business logic.

To find these, you can’t just wait for an attack. You have to actively hunt for them.

The Web and API Vulnerability Scanner will be available first for API Shield customers. Read on to learn why we are focused on API security scans for this first release.

In the web application world, vulnerabilities often look like syntax errors. A SQL injection attempt looks like code where data should be. A cross-site scripting (XSS) attack looks like a script tag in a form field. These have signatures.

API vulnerabilities are different. To illustrate, let’s imagine a food delivery mobile app that communicates solely with an API on the backend. Let’s take the orders endpoint:

Endpoint Definition: /api/v1/orders

In a broken authorization attack like BOLA, User A (the attacker) requests to update the delivery address of a paid-for order belonging to User B (the victim). The attacker simply inserts User B’s {order_id} in the PATCH request.

Here is what that request looks like, with ‘8821’ as User B’s order ID. Notice that User A is fully authenticated with their own valid token:

PATCH /api/v1/orders/8821 HTTP/1.1
Host: api.example.com
Authorization: Bearer <User_A_Valid_Token>
Content-Type: application/json

{
  "delivery_address": "123 Attacker Way, Apt 4",
  "instructions": "Leave at front door, ring bell"
}

The request headers are valid. The authentication token is valid. The schema is correct. To a standard WAF, this request looks perfect. A bot management offering may even be fooled if a human is manually sending the attack requests.

User A will now get B’s food delivered to them! The vulnerability exists because the API endpoint fails to validate if User A actually has permission to view or update user B’s data. This is a failure of logic, not syntax. To fix this, the API developer could implement a simple check: if (order.userID != user.ID) throw Unauthorized;

You can detect these types of vulnerabilities by actively sending API test traffic or passively listening to existing API traffic. Finding these vulnerabilities through passive scanning requires context. Last year we launched BOLA vulnerability detection for API Shield. This detection automatically finds these vulnerabilities by passively scanning customer traffic for usage anomalies. To be successful with this type of scanning, you need to know what a "valid" API call looks like, what the variable parameters are, how a typical user behaves, and how the API behaves when those parameters are manipulated.

Yet there are reasons security teams may not have any of that context, even with access to API Shield’s BOLA vulnerability detection. Development environments may need to be tested but lack user traffic. Production environments may (thankfully) have a lack of attack traffic yet still need analysis, and so on. In these circumstances, and to be proactive in general, teams can turn to Dynamic Application Security Testing (DAST). By creating net-new traffic profiles intended specifically for security testing, DAST tools can look for vulnerabilities in any environment at any time.

Unfortunately, traditional DAST tools have a high barrier to entry. They are often difficult to configure, require you to manually upload and maintain Swagger/OpenAPI files, struggle to authenticate correctly against modern complex login flows, and can simply lack any API-specific security tests (e.g. BOLA).

In the food delivery order example above, we assumed the attacker could find a valid order to modify. While there are often avenues for attackers to gather this type of intelligence in a live production environment, in a security testing exercise you must create your own objects before testing the API’s authorization controls. For typical DAST scans, this can be a problem, because many scanners treat each individual request on its own. This method fails to chain requests together in the logical pattern necessary to find broken authorization vulnerabilities. Legacy DAST scanners can also exist as an island within your security tooling and orchestration environment, preventing their findings from being shared or viewed in context.

Vulnerability scanning from Cloudflare is different for a few key reasons. 

First, Security Insights will list results from our new scans alongside any existing Cloudflare security findings for added context. You’ll see all your posture management information in one place. 

Second, we already know your API’s inputs and outputs. If you are an API Shield customer, Cloudflare already understands your API. Our API Discovery and Schema Learning features passively catalog your endpoints and learn your traffic patterns. While you’ll need to manually upload an OpenAPI spec to get started for our initial release, you will be able to get started quickly without one in a future release.

Third, because we sit at the edge, we can turn passive traffic inspection knowledge into active intelligence. It will be easy to verify BOLA vulnerability detection risks (found via traffic inspection) by sending net-new HTTP requests with the vulnerability scanner.

And finally, we have built a new, stateful DAST platform, as we detail below. Most scanners require hours of setup to "teach" the tool how to talk to your API. With Cloudflare, you can effectively skip that step and get started quickly. You provide the API credentials, and we’ll use your API schemas to automatically construct a scan plan.

APIs are commonly documented using OpenAPI schemas. These schemas denote the host, method, and path (commonly, an “endpoint”) along with the expected parameters of incoming requests and resulting responses. In order to automatically build a scan plan, we must first make sense of these API specifications for any given API to be scanned.

Our scanner works by building up an API call graph from an OpenAPI document and subsequently walking it, using attacker and owner contexts. Owners create resources, attackers subsequently try to access them. Attackers are fully authenticated with their own set of valid credentials. If an attacker successfully reads, modifies or deletes an unowned resource, an authorization vulnerability is found.

Consider for example the above delivery order with ID 8821. For the server-side resource to exist, it needed to be originally created by an owner, most likely in a “genesis” POST request with no or minimal dependencies (previous necessary calls and resulting data). Modelling the API as a call graph, such an endpoint constitutes a node with no or few incoming edges (dependencies). Any subsequent request, such as the attacker’s PATCH above, then has a data dependency (the data is order_id) on the genesis request (the POST). Without all data provided, the PATCH cannot proceed.

Here we see in purple arrows the nodes in this API graph that are necessary to visit to add a note to an order via the POST /api/v1/orders/{order_id}/note/{note_id} endpoint. Importantly, none of the steps or logic shown in the diagram is available in the OpenAPI specification! It must be inferred logically through some other means, and that is exactly what our vulnerability scanner will do automatically.

In order to reliably and automatically plan scans across a variety of APIs, we must accurately model these endpoint relationships from scratch. However, two problems arise: data quality of API specifications is not guaranteed, and even functionally complete schemas can have ambiguous naming schemes. Consider a simplified OpenAPI specification for the above API, which might look like

openapi: 3.0.0
info:
  title: Order API
  version: 1.0.0
paths:
  /api/v1/orders:
    post:
      summary: Create an order
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                product:
                  type: string
                count:
                  type: integer
              required:
                - product
                - count
      responses:
        '201':
          description: Item created successfully
          content:
            application/json:
              schema:
                type: object
                properties:
                  result:
                    type: object
                    properties:
                      id:
                        type: integer
                      created_at:
                        type: integer
                  errors:
                    type: array
                    items:
                      type: string
  /api/v1/orders/{order_id}:
    patch:
      summary: Modify an order by ID
      parameters:
        - name: order_id
          in: path

We can see that the POST endpoint returns responses such as

{
    "result": {
        "id": 8821,
        "created_at": 1741476777
    },
   "errors": []
}

To a human observer, it is quickly evident that $.result.id is the value to be injected in order_id for the PATCH endpoint. The id property might also be called orderId, value or something else, and be nested arbitrarily. These subtle inconsistencies in OpenAPI documents of arbitrary shape are intractable for heuristics-based approaches.

Our scanner uses Cloudflare’s own Workers AI platform to tackle this fuzzy problem space. Models such as OpenAI’s open-weight gpt-oss-120b are powerful enough to match data dependencies reliably, and to generate realistic fake data where necessary, essentially filling in the blanks of OpenAPI specifications. Leveraging structured outputs, the model produces a representation of the API call graph for our scanner to walk, injecting attacker and owner credentials appropriately.

This approach tackles the problem of needing human intelligence to infer authorization and data relationships in OpenAPI schemas with artificial intelligence to do the same. Structured outputs bridge the gap from the natural language world of gpt-oss back to machine-executable instructions. In addition to Workers AI solving the planning problem, self-hosting on Workers AI means our system automatically benefits from Cloudflare’s highly available, globally distributed architecture.

Building a vulnerability scanner that customers will trust with their API credentials demands proven infrastructure. We did not reinvent the wheel here. Instead, we integrated services that have been validated and deployed across Cloudflare for two crucial components of our scanner platform: the scanner’s control plane and the scanner’s secrets store.

The scanner's control plane integrates with Temporal for Scan Orchestration, on which other internal services at Cloudflare already rely. The complexity of the numerous test plans executed in each Scan is effectively managed by Temporal's durable execution framework. 

The entire backend is written in Rust, which is widely adopted at Cloudflare for infrastructure services. This lets us reuse internal libraries and share architectural patterns across teams. It also positions our scanner for potential future integration with other Cloudflare systems like FL2 or our test framework Flamingo – enabling scenarios where scanning could coordinate more tightly with edge request handling or testing infrastructure.

Scanning for broken authentication and broken authorization vulnerabilities requires handling API user credentials. Cloudflare takes this responsibility very seriously.

We ensure that our public API layer has minimal access to unencrypted customer credentials by using HashiCorp's Vault Transit Secret Engine (TSE) for encryption-as-a-service. Immediately upon submission, credentials are encrypted by TSE—which handles the encryption but does not store the ciphertext—and are subsequently stored on Cloudflare infrastructure. 

Our API is not authorized to decrypt this data. Instead, decryption occurs only at the last stage when a TestPlan makes a request to the customer's infrastructure. Only the Worker executing the test is authorized to request decryption, a restriction we strengthen using strict typing with additional safety rails inside Rust to enforce minimal access to decryption methods.

We further secure our customers’ credentials through regular rotation and periodic rewraps using TSE to mitigate risk. This process means we only interact with the new ciphertext, and the original secret is kept unviewable.

We are releasing BOLA vulnerability scanning starting today as an Open Beta for all API Shield customers, and are working on future API threat scans for future release. Via the Cloudflare API, you can trigger scans, manage configuration, and retrieve results programmatically to integrate directly into your CI/CD pipelines or security dashboards. For API Shield Customers: check the developer docs to start scanning your endpoints for BOLA vulnerabilities today.

We are starting with BOLA vulnerabilities because they are the hardest API vulnerability to solve and the highest risk for our customers. However, this scanning engine is built to be extensible.

In the near future, we plan to expand the scanner’s capabilities to cover the most popular of the OWASP Web Top 10 as well: classic web vulnerabilities like SQL injection (SQLi) and cross-site scripting (XSS). To be notified upon release, sign up for the waitlist here, and you’ll be first to learn when we expand the engine to general web application vulnerabilities.

Minor misconfigurations, overlooked firewall events, or request anomalies feel harmless on their own. But when these small signals converge, they can explode into security incidents known as “toxic combinations.” These are exploits where an attacker discovers and compounds many minor issues — such as a debug flag left on a web application or an unauthenticated application path — to breach systems or exfiltrate data.

Cloudflare’s network observes requests to your stack, and as a result, has the data to identify these toxic combinations as they form. In this post, we’ll show you how we surface these signals from our application security data. We’ll go over the most common types of toxic combinations and the dangerous vulnerabilities they present. We will also provide details on how you can use this intelligence to identify and address weaknesses in your stack. 

You could define a "toxic combination" in a few different ways, but here is a practical one based on how we look at our own datasets. Most web attacks eventually scale through automation; once an attacker finds a viable exploit, they'll usually script it into a bot to finish the job. By looking at the intersection of bot traffic, specific application paths, request anomalies and misconfigurations, we can spot a potential breach. We use this framework to reason through millions of requests per second. 

While point defenses like Web Application Firewalls (WAF), bot detection, and API protection have evolved to incorporate behavioral patterns and reputation signals, they still primarily focus on evaluating the risk of an individual request. In contrast, Cloudflare’s detections for "toxic combinations" shift the lens toward the broader intent, analyzing the confluence of context surrounding multiple signals to identify a brewing incident.

^{Toxic combinations as contextualized detections}

That shift in perspective matters because many real incidents have no obvious exploit payload, no clean signatures, and no single event that screams “attack.” So, in what follows, we combine the following context to construct several toxic combinations:

• Bot signals

• Application paths, especially sensitivity ones: admin, debug, metrics, search, payment flows

• Anomalies including: unexpected http codes, geo jumps, identity mismatch, high ID churn, rate-limit evasion (distributed IPs doing the same thing), request or success rate spikes 

• Vulnerabilities or misconfigurations: missing session cookies or auth headers, predictable identifiers

We looked at a 24-hour window of Cloudflare data to see how often these patterns actually appear in popular application stacks. As shown in the table below, about 11% of the hosts we analyzed were susceptible to these combinations, skewed by vulnerable WordPress websites. Excluding WordPress sites, only 0.25% of hosts show signs of exploitable toxic combinations. While rare, they represent hosts that are vulnerable to compromise.

To make sense of the data, we broke it down into three stages of an attack:

• Estimated hosts probed: This is the "wide net." It counts unique hosts where we saw HTTP requests targeting specific sensitive paths (like /wp-admin).

• Estimated hosts filtered by toxic combination: Here, we narrowed the list down to the specific hosts that actually met our criteria for a toxic combination.

• Estimated reachable hosts: Unique hosts that responded successfully to an exploit attempt—the "smoking gun" of an attack. A simple 200 OK response (such as one triggered by appending ?debug=true) could be a false positive. We validated paths to filter out noise caused by authenticated paths that require credentials despite the 200 status code, redirects that mask the true exploit path, and origin misconfigurations that serve success codes for unreachable paths.

In the next sections, we’ll dig into the specific findings and the logic behind the combinations that drove them. The detection queries provided are necessary but not sufficient without testing for reachability; it is possible that the findings might be false positives. In some cases, Cloudflare Log Explorer allows these queries to be executed on unsampled Cloudflare logs. 

Table 1. Summary of Toxic Combinations

We observed automated tools scanning common administrative login pages — like WordPress admin panels (/wp-admin), database managers, and server dashboards. A templatized version of the query, executable in Cloudflare Log Explorer, is below:

SELECT
  clientRequestHTTPHost,
  COUNT(*) AS request_count
FROM
  http_requests 
WHERE
  timestamp >= '{{START_DATE}}'
  AND timestamp <= '{{END_DATE}}'
  AND edgeResponseStatus = 200
  AND clientRequestPath LIKE '{{PATH_PATTERN}}' //e.g. '%/wp-admin/%'
  AND NOT match( extract(clientRequestHTTPHost, '^[^:/]+'), '^\\d{1,3}(\\.\\d{1,3}){3}(:\\d+)?$') // comment this line for Cloudflare Log Explorer
  AND botScore < {{BOT_THRESHOLD}} // we used botScore < 30
GROUP BY
  clientRequestHTTPHost
ORDER BY
  request_count DESC;

Publicly accessible admin panels can enable brute force attacks. If successful, an attacker can further compromise the host by adding it to a botnet that probes additional websites for similar vulnerability. In addition, this toxic combination can lead to:

• Exploit scanning: Attackers identify the specific software version you're running (like Tomcat or WordPress) and launch targeted exploits for known vulnerabilities (CVEs).

• User enumeration: Many admin panels accidentally reveal valid usernames, which helps attackers craft more convincing phishing or login attacks.

Toxic combination of bots automation and exposed management interfaces like: /wp-admin/, /admin/, /administrator/, /actuator/*, /_search/, /phpmyadmin/, /manager/html/, and /app/kibana/.

1. Implement Zero Trust Access. 

2. If for any reason the endpoint has to remain public, implement a challenge platform to add friction to bots.

3. Implement IP allowlist: Use your WAF or server configuration to ensure that administrative paths are only reachable from your corporate VPN or specific office IP addresses.

4. Cloak admin paths: If your platform allows it, rename default admin URLs (e.g., change /wp-admin to a unique, non-guessable string).

5. Deploy geo-blocking: If your administrators only operate from specific countries, block all traffic to these sensitive paths coming from outside those regions.

6. Enforce multi-factor authentication (MFA): Ensure every administrative entry point requires a second factor; a password alone is not enough to stop a dedicated crawler.

We found API endpoints that are accessible to anyone on the Internet without a password or login (see OWASP: API2:2023 – Broken Authentication). Even worse, the way it identifies records (using simple, predictable ID numbers,see OWASP: API1:2023- Broken Object Level Authorization) allows anyone to simply "count" through your database — making it much simpler for attackers to enumerate and “scrape” your business records, without even visiting your website directly.

SELECT
  uniqExact(clientRequestHTTPHost) AS unique_host_count
FROM  http_requests
WHERE timestamp >= '2026-02-13'
  AND timestamp <= '2026-02-14'
  AND edgeResponseStatus = 200
  AND bmScore < 30
  AND (
       match(extract(clientRequestQuery, '(?i)(?:^|[&?])uid=([^&]+)'),  '^[0-9]{3,10}$')
    OR match(extract(clientRequestQuery, '(?i)(?:^|[&?])user=([^&]+)'), '^[0-9]{3,10}$')
    OR length(extract(clientRequestQuery, '(?i)(?:^|[&?])uid=([^&]+)'))  BETWEEN 3 AND 8
    OR length(extract(clientRequestQuery, '(?i)(?:^|[&?])user=([^&]+)')) BETWEEN 3 AND 8
  )

This is a "zero-exploit" vulnerability, meaning an attacker doesn't need to be a hacker to steal your data; they just need to change a number in a web link. This leads to:

• Mass Data Exposure: Large-scale scraping of your entire customer dataset.

• Secondary Attacks: Stolen data is used for targeted phishing or account takeovers.

• Regulatory Risk: Severe privacy violations (GDPR/CCPA) due to exposing sensitive PII.

• Fraud: Competitors or malicious actors gaining insight into your business volume and customer base.

Toxic combination of missing security controls and automation targeting particular API endpoints.

While the query checked for bot score and predictable identifiers, signals like high cardinality, stable response sizes and missing authentication were tested on a sample of traffic matching the query. 

1. Enforce authentication: Immediately require a valid session or API key for the affected endpoint. Do not allow "Anonymous" access to data containing PII or business secrets.

2. Implement authorization (IDOR check): Ensure the backend checks that the authenticated user actually has permission to view the specific tid they are requesting.

3. Use UUIDs: Replace predictable, sequential integer IDs with long, random strings (UUIDs) to make "guessing" identifiers computationally impossible.

4. Deploy API Shield: Enable Cloudflare API Shield with features like Schema Validation (to block unexpected inputs) and BOLA Detection.

We found evidence of debug=true appended to web paths to reveal system details. A templatized version of the query, executable in Cloudflare Log Explorer, is below:

SELECT
  clientRequestHTTPHost,
  COUNT(rayId) AS request_count
FROM
  http_requests
WHERE
  timestamp >= '{{START_TIMESTAMP}}'
  AND timestamp < '{{END_TIMESTAMP}}'
  AND edgeResponseStatus = 200
  AND clientRequestQuery LIKE '%debug=false%'
  AND botScore < {{BOT_THRESHOLD}}
GROUP BY
  clientRequestHTTPHost
ORDER BY
  request_count DESC;

While this doesn't steal data instantly, it provides an attacker with a high-definition map of your internal infrastructure. This "reconnaissance" makes their next attack much more likely to succeed because they can see:

• Hidden data fields: Sensitive internal information that isn't supposed to be visible to users.

• Technology stack details: Specific software versions and server types, allowing them to look up known vulnerabilities for those exact versions.

• Logic hints: Error messages or stack traces that explain exactly how your code works, helping them find ways to break it.

Toxic combination of automated probing and misconfigured diagnostic flags targeting the Multiple Hosts and Application Paths.

While the query checked for bot score and paths with debug parameters, signals like repeated probing, response sizes and schema disclosure were tested on a sample of traffic matching the query. 

1. Disable debugging in production: Ensure that all "debug" or "development" environment variables are strictly set to false in your production deployment configurations.

2. Filter parameters at the edge: Use your WAF or API Gateway to strip out known debug parameters (like ?debug=, ?test=, ?trace=) before they ever reach your application servers.

3. Sanitize error responses: Configure your web servers (Nginx, Apache, etc.) to show generic error pages instead of detailed stack traces or internal system messages.

4. Audit firebase/DB rules: If you are using Firebase or similar NoSQL databases, ensure that /.json path access is restricted via strict security rules, so public users cannot dump the entire schema or data.

We discovered "health check" and monitoring dashboards are visible to the entire Internet. Specifically, paths like /actuator/metrics are responding to anyone who asks. A templatized version of the query, executable in Cloudflare Log Explorer, is below::

SELECT
  clientRequestHTTPHost,
  count() AS request_count
FROM http_requests
WHERE timestamp >= toDateTime('{{START_DATE}}')
  AND timestamp <  toDateTime('{{END_DATE}}')
  AND botScore < 30
  AND edgeResponseStatus = 200
  AND clientRequestPath LIKE '%/actuator/metrics%' // an example
GROUP BY
  clientRequestHTTPHost
ORDER BY request_count DESC

Why is this serious?

While these endpoints don't usually leak customer passwords directly, they provide the "blueprints" for a sophisticated attack. Exposure leads to:

• Strategic timing: Attackers can monitor your CPU and memory usage in real-time to launch a Denial of Service (DoS) attack exactly when your systems are already stressed.

• Infrastructure mapping: These logs often reveal the names of internal services, dependencies, and version numbers, helping attackers find known vulnerabilities to exploit.

• Exploitation chaining: Information about thread counts and environment hints can be used to bypass security layers or escalate privileges within your network.

Toxic combination of misconfigured access controls and automated reconnaissance targeting the Asset/Path: /actuator/metrics, /actuator/prometheus, and /health.

1. Restrict access via WAF: Immediately create a firewall rule to block any external traffic requesting paths containing /actuator/ or /prometheus.

2. Bind to localhost: Reconfigure your application frameworks to only serve these monitoring endpoints on localhost (127.0.0.1) or a private management network.

3. Enforce basic auth: If these must be accessed over the web, ensure they are protected by strong authentication (at a minimum, complex Basic Auth or mTLS).

4. Disable unnecessary endpoints: In Spring Boot or similar frameworks, disable any "Actuator" features that are not strictly required for production monitoring.

Search endpoints (like Elasticsearch or OpenSearch) that are usually meant for internal use are wide open to the public. The templatized query is:

SELECT
  clientRequestHTTPHost,
  count() AS request_count
FROM http_requests
WHERE timestamp >= toDateTime('{{START_DATE}}')
  AND timestamp <  toDateTime('{{END_DATE}}')
  AND botScore < 30
  AND edgeResponseStatus = 200
AND clientRequestPath like '%/\_search%'
AND NOT match(extract(clientRequestHTTPHost, '^[^:/]+'), '^\\d{1,3}(\\.\\d{1,3}){3}(:\\d+)?$')
GROUP BY
  clientRequestHTTPHost

This is a critical vulnerability because it requires zero technical skill to exploit, yet the damage is extensive:

• Mass data theft: Attackers can "dump" entire indices, stealing millions of records in minutes.

• Internal reconnaissance: By viewing your "indices" (the list of what you store), attackers can identify other high-value targets within your network.

• Data sabotage: Depending on the setup, an attacker might not just read data — they could potentially modify or delete your entire search index, causing a massive service outage.

We are seeing a toxic combination of misconfigured exposure and automated traffic and data enumeration targeting  /_search, /_cat/indices, and /_cluster/health.

While the query checked for bot score and paths, signals like repeated query patterns, response sizes, and schema disclosure were tested on a sample of traffic matching the query. 

1. Restrict network access: Immediately update your Firewall/Security Groups to ensure that search ports (e.g., 9200, 9300) and paths are only accessible from specific internal IP addresses.

2. Enable authentication: Turn on "Security" features for your search cluster (like Shield or Search Guard) to require valid credentials for every API call.

3. WAF blocking: Deploy a WAF rule to immediately block any request containing /_search, /_cat, or /_cluster coming from the public Internet.

4. Audit for data loss: Review your database logs for large "Scroll" or "Search" queries from unknown IPs to determine exactly how much data was exfiltrated.

We’ve identified attackers who sent a malicious request—specifically a SQL injection designed to trick databases. A templatized version of the query, executable in Cloudflare Log Explorer, is below:

SELECT
  clientRequestHTTPHost,
  count() AS request_count
FROM http_requests
WHERE timestamp >= toDateTime('{{START_DATE}}')
  AND timestamp <  toDateTime('{{END_DATE}}')
  AND botScore < 30
AND wafmlScore<30
  AND edgeResponseStatus = 200
AND LOWER(clientRequestQuery) LIKE '%sleep(%'
GROUP BY
  clientRequestHTTPHost
ORDER BY request_count DESC

This is the "quiet path" to a data breach. Because the system returned a successful status code (HTTP 200), these attacks often blend in with legitimate traffic. If left unaddressed, an attacker can:

• Refine their methods: Use trial and error to find the exact payload that bypasses your filters.

• Exfiltrate data: Slowly drain database contents or leak sensitive secrets (like API keys) passed in URLs.

• Stay invisible: Most automated alerts look for "denied" attempts; a "successful" exploit is much harder to spot in a sea of logs.

We are seeing a toxic combination of automated bot signals, anomalies and application-layer vulnerabilities targeting many application paths.

1. Immediate virtual patching: Update your WAF rules to specifically block the SQL patterns identified (e.g., time-based probes).

2. Sanitize inputs: Review the backend code for this path to ensure it uses prepared statements or parameterized queries.

3. Remediate secret leakage: Move any sensitive data from URL parameters to the request body or headers. Rotate any keys flagged as leaked.

4. Audit logs: Check database logs for the timeframe of the "HTTP 200" responses to see if any data was successfully extracted.

Card testing and card draining are some of the most common fraud tactics. An attacker might buy a large batch of credit cards from the dark web. Then, to verify how many cards are still valid, they might test the card on a website by making small transactions. Once validated, they might use such cards to make purchases, such as gift cards, on popular shopping destinations. 

On payment flows (/payment, /checkout, /cart), we found certain hours of the day when either the hourly request volume from bots or hourly payment success ratio spiked by more than 3 standard deviations from their hourly baselines over the prior 30 days. This could be related to card testing where an attacker is trying to validate lots of stolen credits. Of course, marketing campaigns might cause request spikes while payment outages might cause sudden drops in success ratios.

Payment success ratio drops coinciding with request spikes, in the absence of marketing campaigns or payment outages or other factors, could mean bots are in the middle of a massive card-testing run.

We used a combination of bot signals and anomalies on /payment, /checkout, /cart:

Use the 30-day payment paths hourly request volume baseline as the hourly rate limit for all requests with bot scores < 30 on payment paths.  

On payment flows (/payment, /checkout, /cart), we found certain hours of the day when either the hourly request volume from humans (or bots impersonating humans) or hourly payment success ratio spiked by more than 3 standard deviations from their hourly baselines over the prior 30 days. This could be related to card draining where an attacker (either humans or bots impersonating humans) is trying to purchase goods using valid but stolen credits. Of course, marketing campaigns might also cause request and success ratio spikes, so additional context in the form of typical payment requests from a given IP address is essential context, as shown in the figure.

Payment success ratio spikes coinciding with request spikes and high density of requests per IP address, in the absence of marketing campaigns or payment outages or other factors, could mean humans (or bots pretending to be humans) are making fraudulent purchases. Every successful transaction here could be a direct revenue loss or a chargeback in the making.

We used a combination of bot signals and anomalies on /payment, /checkout, /cart:

Identity-Based Rate Limiting: Use IP density to implement rate limits for requests with bot score >=30 on payment endpoints.

Monitor success ratio: Alert on any hour when the success ratio for "human" traffic, with bot score >=30 on payment endpoints, deviates by more than 3 standard deviations from its 30-day baseline.

Challenge: If a high bot score request (likely human) hits payment flows more than 3 times in 10 minutes, trigger a challenge to slow them down

We are currently working on integrating these "toxic combination" detections directly into the Security Insights dashboard to provide immediate visibility for such risks. Our roadmap includes building AI-assisted remediation paths — where the dashboard doesn't just show you a toxic combination, but proposes the specific WAF rule or API Shield configuration required to neutralize it.

We would love to have you try our Security Insights featuring toxic combinations. You can join the waitlist here. 

We spend Birthday Week every year releasing the products and capabilities we believe the Internet needs at this moment and around the corner. Previous Birthday Weeks saw the launch of IPv6 gateway in 2011,  Universal SSL in 2014, Cloudflare Workers and unmetered DDoS protection in 2017, Cloudflare Radar in 2020, R2 Object Storage with zero egress fees in 2021,  post-quantum upgrades for Cloudflare Tunnel in 2022, Workers AI and Encrypted Client Hello in 2023. And those are just a sample of the launches.

This year’s themes focused on helping prepare the Internet for a new model of monetization that encourages great content to be published, fostering more opportunities to build community both inside and outside of Cloudflare, and evergreen missions like making more features available to everyone and constantly improving the speed and security of what we offer.

We shipped a lot of new things this year. In case you missed the dozens of blog posts, here is a breakdown of everything we announced during Birthday Week 2025. 

Monday, September 22

Tuesday, September 23

Wednesday, September 24

Thursday, September 25

Friday, September 26

Helping build a better Internet has always been about more than just technology. Like the announcements about interns or working together in our offices, the community of people behind helping build a better Internet matters to its future. This week, we rolled out our most ambitious set of initiatives ever to support the builders, founders, and students who are creating the future.

For founders and startups, we are thrilled to welcome Cohort #6 to the Workers Launchpad, our accelerator program that gives early-stage companies the resources they need to scale. But we’re not stopping there. We’re opening our doors, literally, by launching new physical hubs for startups in our San Francisco, Austin, London, and Lisbon offices. These spaces will provide access to mentorship, resources, and a community of fellow builders.

We’re also investing in the next generation of talent. We announced free access to the Cloudflare developer platform for all students, giving them the tools to learn and experiment without limits. To provide a path from the classroom to the industry, we also announced our goal to hire 1,111 interns in 2026 — our biggest commitment yet to fostering future tech leaders.

And because a better Internet is for everyone, we’re extending our support to non-profits and public-interest organizations, offering them free access to our production-grade developer tools, so they can focus on their missions.

Whether you're a founder with a big idea, a student just getting started, or a team working for a cause you believe in, we want to help you succeed.

Thank you to our customers, our community, and the millions of developers who trust us to help them build, secure, and accelerate the Internet. Your curiosity and feedback drive our innovation.

It’s been an incredible 15 years. And as always, we’re just getting started!

(Watch the full conversation on our show ThisWeekinNET.com about what we launched during Birthday Week 2025 here.)

To fix this, Cloudflare is working towards a set of solutions that consolidates all SaaS connections via a single proxy, for easier monitoring, detection and response. A SaaS to SaaS proxy for everyone.

As we build this, we need feedback from the community, both data owners and SaaS platform providers. If you are interested in gaining early access, please sign up here.

SaaS platform providers, who often offer marketplaces for additional applications, store data on behalf of their customers and ultimately become the trusted guardians. As integrations with marketplace applications take place, that guardianship is put to the test. A key breach in any one of these integrations can lead to widespread data exfiltration and tampering. As more apps are added the attack surface grows larger. Security teams who work for the data owner have no ability, today, to detect and react to any potential breach.

In this post we explain the underlying technology required to make this work and help keep your data on the Internet safe.

No one disputes the value provided by SaaS applications and their integrations. Major SaaS companies implement flourishing integration ecosystems, often presented as marketplaces. For many, it has become part of their value pitch. Salesforce provides an AppExchange. Zendesk provides a marketplace. ServiceNow provides an Integration Hub. And so forth.

These provide significant value to any organisation and complex workflows. Data analysis or other tasks that are not supported natively by the SaaS vendor are easily carried out via a few clicks.

On the other hand, SaaS applications present security teams with a growing list of unknowns. Who can access this data? What security processes are put in place? And more importantly: how do we detect data leak, compromise, or other malicious intent?

Following the Salesloft breach, which compromised the data of hundreds of companies, including Cloudflare, the answers to these questions are top of mind.

There are two approaches Cloudflare is actively prototyping to address the growing security challenges SaaS applications pose, namely visibility into SaaS to SaaS connections, including anomaly detection and key management in the event of a breach. Let’s go over each of these, both relying on proxying SaaS to SaaS traffic.

Cloudflare runs one of the world’s largest reverse proxy networks. As we terminate L7 traffic, we are able to perform security-related functions including blocking malicious requests, detecting anomalies, detecting automated traffic and so forth. This is one of the main use cases customers approach us for.

Cloudflare can proxy any hostname under the customer’s control.

It is this specific ability, often referred to as “vanity”, “branded” or “custom” hostnames, that allows us to act as a front door to the SaaS vendor on behalf of a customer. Provided a marketplace app integrates via a custom domain, the data owner can choose to use Cloudflare’s new SaaS integration protection capabilities.

For a customer (Acme Corp in this example) to access, say SaaS Application, the URL needs to become saas.acme.com as that is under Acme’s control (and not acme.saas.com).

This setup allows Cloudflare to be placed in front of SaaS Corp as the customer controls the DNS hostname. By proxying traffic, Cloudflare can be the only integration entity with programmatic access to SaaS Corp's APIs and data and transparently "swap" authorisation tokens with valid ones and issue separate tokens, using key splitting, to any integrations. 

Note that in many cases, authorization and authentication flows fall outside any vanity/branded hostname. It is in fact very common for an OAuth flow to still hit the SaaS provider url oauth.saas.com. It is therefore required, in this setup, for marketplace applications to provide the ability to support vanity/branded URLs for their OAuth and similar flows, oauth.saas.acme.com in the diagram above.

Ultimately Cloudflare provides a full L7 reverse proxy for all traffic inbound/outbound to the given SaaS provider solving for the core requirements that would lessen the impact of a similar breach to the Salesloft example. Had Salesloft integrated via a Cloudflare-proxied domain, then data owners would be able to:

• Gain visibility into who or what can access data, and where it’s accessed from, in the SaaS platform. Cloudflare already provides analytics and filtering tools to identify traffic sources, including hosting locations, IPs, user agents and other tools.

• Instantly shut off access to the SaaS provider without the need to rotate credentials on the SaaS platform, as Cloudflare would be able to block access from the proxy.

• Detects anomalies in data access by observing baselines and traffic patterns. For example a change in data exfiltration traffic flows would trigger an alert.

The approach listed above assumes the end user is the company whose data is at risk. However, SaaS platforms themselves are now paying a lot of attention to marketplace applications and access patterns. From a deployment perspective, it’s actually easier to provide additional visibility to a SaaS provider as it is a standard reverse proxy deployment and we have tools designed for SaaS applications, such as Cloudflare for SaaS.

This deployment model allows Cloudflare to proxy all traffic to the SaaS vendor, including to all API endpoints therefore gaining visibility into any SaaS to SaaS connections. As part of this, we are building improvements to our API Shield solution to provide SaaS security teams with additional controls:

• Token / session logging: Ability to keep track of OAuth tokens and provide session logs for audit purposes.

• Session anomaly detection: Ability to warn when a given OAuth (or other session) shows anomalous behavior.

• Token / session replacement: Ability to substitute SaaS-generated tokens with Cloudflare-generated tokens to allow for fast rotation and access lock down.

The SaaS vendor may of course expose some of the affordances to their end customer as part of their dashboard.

Both deployment approaches described above rely on our ability to control access without storing complete credentials. While we already store SSL/TLS private keys for millions of web applications, storing complete SaaS bearer tokens would create an additional security burden. To solve this, and enable the token swapping and instant revocation capabilities mentioned above, we use key splitting.

Key splitting cryptographically divides bearer tokens into two mathematically interdependent fragments called Part A and Part B. Part A goes to the fourth-party integration (like Drift or Zapier) while Part B stays in Cloudflare's edge storage. Part A is just random noise that won't authenticate to Salesforce or any SaaS platform expecting complete tokens, so neither fragment is usable alone.

This creates an un-bypassable control point. Integrations cannot make API calls without going through Cloudflare's proxy because they only possess Part A. When an integration needs to access data, it must present Part A to our edge where we retrieve Part B, reconstruct the token in memory for microseconds, forward the authenticated request, and then immediately clear the token. This makes sure that the complete bearer token never exists in any database or log.

This forced cooperation means every API call flows through Cloudflare where we can monitor for anomalies, delete Part B to instantly revoke access (transforming incident response from hours to seconds), and maintain complete audit trails. Even more importantly, this approach minimizes our burden of storing sensitive credentials since a breach of our systems wouldn't yield usable tokens.

If attackers compromise the integration and steal Part A, or somehow breach Cloudflare's storage and obtain Part B, neither fragment can authenticate on its own. This fundamentally changes the security model from protecting complete tokens to managing split fragments that are individually worthless. It also gives security teams unprecedented visibility and control over how their data is accessed across third-party integrations.

We are excited to develop solutions mentioned above to give better control and visibility around data stored in SaaS environments, or more generally, outside a customer’s network.

If you are a company worried about this risk, and would like to be notified to take part in our early access, please sign up here.

If you are a SaaS vendor who would like to provide feedback and take part in developing better API security tooling for third party integrations towards your platform, sign up here.

We are looking forward to helping you get better control of your data in SaaS to SaaS environments.

As we continuously work to meet new challenges, Innovation Weeks like Security Week give us an invaluable opportunity to share our point of view and engage with the wider Internet community. Cloudflare’s mission is to help build a better Internet. We want to help safeguard the Internet from the arrival of quantum supercomputers, help protect the livelihood of content creators from unauthorized AI scraping, help raise awareness of the latest Internet threats, and help find new ways to help reduce the reuse of compromised passwords. Solving these challenges will take a village. We’re grateful to everyone who has engaged with us on these issues via social media, contributed to our open source repositories, and reached out through our technology partner program to work with us on the issues most important to them. For us, that’s the best part.

Here’s a recap of this week’s announcements:

For a deeper dive on many of the great announcements from Security Week, check out our CFTV segments where our team shares even more details on our latest updates. 

We appreciate everyone who’s taken the time to read Cloudflare’s Security Week blog posts or engage with us on these topics via social media. Our next innovation week, Developer Week, is right around the corner in April. We look forward to seeing you then!

“Cloudflare is a strong option for customers that want to manage an easy-to-use, unified web application protection platform that will continue to innovate.”

In this evaluation, Forrester assessed 10 Web Application Firewall (WAF) vendors across 22 criteria, including product security and vision. We believe this recognition is due to our continued investment in our product offering. Get a complimentary copy of the report here.

Since introducing our first WAF in 2013, Cloudflare has transformed it into a robust, enterprise-grade Application Security platform. Our fully integrated suite includes WAF, bot mitigation, API security, client-side protection, and DDoS mitigation, all built on our expansive global network. By leveraging AI and machine learning, we deliver industry-leading security while enhancing application performance through our content delivery and optimization solutions.

According to the Forrester report, “Cloudflare stands out with features that help customers work more efficiently.” Unlike other solutions in the market, Cloudflare’s WAF, API Security, bot detection, client-side security, and DDoS protection are natively integrated within a single platform, running on a unified engine. Our integrated solution empowers a seamless user experience and enables advanced threat detection across multiple vectors to meet the most demanding security requirements.

Forrester’s evaluation of Web Application Firewall solutions is one of the most comprehensive assessments in the industry. We believe this report highlights Cloudflare’s integrated global cloud platform and our ability to deliver enterprise-grade security without added complexity. We don’t just offer a WAF — we provide a flexible, customizable security toolkit designed to address your unique application security challenges.

Cloudflare continuously leads the WAF market through our strategic vision and the breadth of our capabilities. We center our approach on relentless innovation, delivering industry-leading security features, and ensuring a seamless management experience with enterprise processes and tools such as Infrastructure as Code (IaC) and DevOps. Our predictable cadence of major feature releases, powered by annual initiatives like Security Week and Birthday Week, ensures that customers always have access to the latest security advancements.

We believe Forrester also highlighted Cloudflare’s extensive security capabilities, with particular recognition of the significant improvements in our API security offerings.

In the report, Cloudflare received the highest possible scores in 15 out of 22 criteria, reinforcing, in our opinion, our commitment to delivering the most advanced, flexible and easy-to-use web application protection in the industry. Some of the key criteria include:

• Detection models: Advanced AI and machine learning models that continuously evolve to detect new threats.

• Layer 7 DDoS protection: Industry-leading mitigation of sophisticated application-layer attacks.

• Rule creation and modification: Simple, easy to use rule creation experience, propagating within seconds globally.

• Management UI: An intuitive and efficient user interface that simplifies security management.

• Product security: A robust architecture that ensures enterprise-grade security.

• Infrastructure-as-code support: Seamless integration with DevOps workflows for automated security policy enforcement.

• Innovation: A forward-thinking approach to security, consistently pushing the boundaries of what’s possible.

First, Cloudflare’s WAF goes beyond traditional rule-based protections, offering a comprehensive suite of detection mechanisms to identify attacks and vulnerabilities across web and API traffic while also safeguarding client environments. We leverage AI and machine learning to detect threats such as attacks, automated traffic, anomalies, and compromised JavaScript, among others. Our industry-leading application-layer DDoS protection makes volumetric attacks a thing of the past.

Second, Cloudflare has also made significant strides in API security. Our WAF can be supercharged with features such as: API discovery, schema validation & sequence mitigation, volumetric detection, and JWT authentication. 

Third, Cloudflare simplifies security management with an intuitive dashboard that is easy to use while still offering powerful configurations for advanced practitioners. All features are Terraform-supported, allowing teams to manage the entire Cloudflare platform as code. With Security Analytics, customers gain a comprehensive view of all traffic, whether mitigated or not, and can run what-if scenarios to test new rules before deployment. This analytic capability ensures that businesses can dynamically adapt their security posture while maintaining high performance. To make security management even more seamless, our AI agent, powered by Natural Language Processing (NLP), helps users craft and refine custom rules and create powerful visualizations within our analytics engine.

We are confident that Forrester’s report validates what our customers already know: Cloudflare is a leading WAF vendor, offering unmatched security, innovation, and ease of use. As threats continue to evolve, we remain committed to pushing the boundaries of web security to protect organizations worldwide.

If you’re looking for a powerful, scalable, and easy-to-manage web application firewall, Cloudflare is the best choice for securing your applications, APIs, and infrastructure.

Learn more about Cloudflare WAF by creating an account today and see why Forrester has recognized us as a leader in the market. 

Forrester does not endorse any company, product, brand, or service included in its research publications and does not advise any person to select the products or services of any company or brand based on the ratings included in such publications. Information is based on the best available resources. Opinions reflect judgment at the time and are subject to change. For more information, read about Forrester’s objectivity here .

This separation, which has sometimes guided implementation decisions that have led to different systems being built for the same purpose, makes it harder for our users to adopt our features and implement a simple effective security posture for their environment.

Today, following user feedback and our drive to constantly innovate and simplify, we are going back to our roots by breaking these artificial product boundaries and revising our dashboard, so it highlights our strengths. The ultimate goal remains: to make it shockingly easy to secure your web assets.

Introducing a new unified Application Security experience.

If you are a Cloudflare Application Security user, log in to the dashboard today and try out the updated dashboard interface. To make the transition easier, you can toggle between old and new interfaces.

Modern applications are built using a variety of technologies. Your app might include a web interface and a mobile version, both powered by an API, each with its own unique security requirements. As these technologies increasingly overlap, traditional security categories like Web, API, client-side, and bot protection start to feel artificial and disconnected when applied to real-world application security.

Consider scenarios where you want to secure your API endpoints with proper authentication, or prevent vulnerability scanners from probing for weaknesses. These tasks often require switching between multiple dashboards, creating different policies, and managing disjointed configurations. This fragmented approach not only complicates workflows but also increases the risk of overlooking a critical vulnerability. The result? A security posture that is harder to manage and potentially less effective.

When you zoom out, a pattern emerges. Whether it’s managing bots, securing APIs, or filtering web traffic, these solutions ultimately analyze incoming traffic looking for specific patterns, and the resulting signal is used to perform actions. The primary difference between these tools is the type of signal they generate, such as identifying bots, enforcing authorization, or flagging suspicious requests. 

At Cloudflare, we saw an opportunity to address this complexity by unifying our application security tools into a single platform with one cohesive UI. A unified approach means security practitioners no longer have to navigate multiple interfaces or piece together different security controls. With a single UI, you can configure policies more efficiently, detect threats faster, and maintain consistent protection across all aspects of your application. This simplicity doesn’t just save time, it ensures that your applications remain secure, even as threats evolve.

At the end of the day, attackers won’t care which product you’re using. But by unifying application security, we ensure they’ll have a much harder time finding a way in.

To redefine the experience across Application Security products, we can start by defining three concepts that commonly apply:

• Web traffic (HTTP/S), which can be generalised even further as “data”

• Signals and detections, which provide intelligence about the traffic. Can be generalised as “metadata”

• Security rules that let you combine any signal or detection (metadata), to block, challenge or otherwise perform an action on the web traffic (data)

We can diagram the above as follows:

Using these concepts, all the product groupings that we offer can be converted to different types of signals or detections. All else remains the same. And if we are able to run and generate our signals on all traffic separately from the rule system, therefore generating all the metadata, we get what we call always-on detections, another vital benefit of a single platform approach. Also note that the order in which we generate the signals becomes irrelevant.

In diagram form:

The benefits are twofold. First, problem spaces (such as account takeover or web attacks) become signal groupings, and therefore metadata that can be queried to answer questions about your environment.

For example, let’s take our Bot Management signal, the bot score, and our WAF Attack Score signal, the attack score. These already run as always-on detections at Cloudflare. By combining these two signals and filtering your traffic against them, you can gain powerful insights on who is accessing your application*:

Second, as everything is just a signal, the mitigation layer, driven by the optional rules, becomes detection agnostic. By providing the same signals as fields in a unified rule system, writing high level policies becomes a breeze. And as we said earlier, given the detection is always-on and fully separated from the mitigation rule system, exploring the data can be thought of as a powerful rule match preview engine. No need to deploy a rule in LOG mode to see what it matches!

We can now design a unified user experience that reflects Application Security as a single product.

^{* note: the example here is simplistic, and the use cases become a lot more powerful once you expand to the full set of potential signals that the platform can generate. Take, for example, our ability to detect file uploads. If you run a job application site, you may want to let crawlers access your site, but you may *not* want crawlers to submit applications on behalf of applicants. By combining the bot score signal with the file upload signal, you can ensure that rule is enforced.}

As signals are always-on, the user journey can now start from our new overview page where we highlight security suggestions based on your traffic profile and configurations. Alternatively, you can jump straight into analytics where you can investigate your traffic using a combination of all available signals.

When a specific traffic pattern seems malicious, you can jump into the rule system to implement a security policy. As part of our new design, given the simplicity of the navigation, we also took advantage of the opportunity to introduce a new web assets page, where we highlight discovery and attack surface management details.

Of course, reaching the final design required multiple iterations and feedback sessions. To best understand the balance of maintaining flexibility in the UI whilst reducing complexity, we focused on customer tasks to be done and documenting their processes while trying to achieve their intended actions in the dashboard. Reducing navigation items and using clear naming was one element, but we quickly learned that the changes needed to support ease of use for tasks across the platform.

Here is the end result:

To recap, our new dashboard now includes:

• One overview page where misconfigurations, risks, and suggestions are aggregated

• Simplified and redesigned security analytics that surfaces security signals from all Application Security capabilities, so you can easily identify and act on any suspicious activity

• A new web assets page, where you can manage your attack surfaces, helping improve detection relevance

• A single Security Rules page that provides a unified interface to manage, prioritise, and customise all mitigation rules in your zone, significantly streamlining your security configuration

• A new settings page where advanced control is based on security needs, not individual products

Let’s dive into each one.

With the unified security approach, the new overview page aggregates and prioritizes security suggestions across all your web assets, helping you maintain a healthy security posture. The suggestions span from detected (ongoing) attacks if there are any, to risks and misconfigurations to further solidify your protection. This becomes the daily starting point to manage your security posture.

Security Analytics and Events have been redesigned to make it easier to analyze your traffic. Suspicious activity detected by Cloudflare is surfaced at the top of the page, allowing you to easily filter and review related traffic. From the Traffic Analytics Sampled Log view, further below in the page, new workflows enable you to take quick action to craft a custom rule or review related security events in context.

Web assets is a new concept introduced to bridge your business goals with threat detection capabilities. A web asset is any endpoint, file, document, or other related entity that we normally would act on from a security perspective. Within our new web asset page, you will be able to explore all relevant discovered assets by our system.

With our unified security platform, we are able to rapidly build new use-case driven threat detections. For example, to block automated actions across your e-commerce website, you can instruct Cloudflare’s system to block any fraudulent signup attempts, while allowing verified crawlers to index your product pages. This is made possible by labelling your web assets, which, where possible, is automated by Cloudflare, and then using those labels to power threat detections to protect your assets.

The unified Security rules interface brings all mitigation rule types — including WAF custom rules, rate limiting rules, API sequence rules, and client side rules — together in one centralized location, eliminating the need to navigate multiple dashboards.

The new page gives you visibility into how Cloudflare mitigates both incoming traffic and blocks potentially malicious client side resources from loading, making it easier to understand your security posture at a glance. The page allows you to create customised mitigation rules by combining any detection signals, such as Bot Score, Attack Score, or signals from Leaked Credential Checks, enabling precise control over how Cloudflare responds to potential threats.

Balancing guidance and flexibility was the key driver for designing the new Settings page. As much as Cloudflare guides you towards the optimal security posture through recommendations and alerts, customers that want the flexibility to proactively adjust these settings can find all of them here.

This is the first of many enhancements we plan to make to the Application Security experience in the coming months. To check out the new navigation, log in to the Cloudflare dashboard, click on “Security” and choose “Check it out” when you see the message below. You will still have the option of opting out, if you so prefer.

Let us know what you think either by sharing feedback in our community forum or by providing feedback directly in the dashboard (you will be prompted if you revert to the old design).

In Cloudflare’s bot detection, we build heuristics from attributes like software library fingerprints, HTTP request characteristics, and internal threat intelligence. Heuristics serve three separate purposes for bot detection: 

1. Bot identification: If traffic matches a heuristic, we can identify the traffic as definitely automated traffic (with a bot score of 1) without the need of a machine learning model. 

2. Train ML models: When traffic matches our heuristics, we create labelled datasets of bot traffic to train new models. We’ll use many different sources of labelled bot traffic to train a new model, but our heuristics datasets are one of the highest confidence datasets available to us.   

3. Validate models: We benchmark any new model candidate’s performance against our heuristic detections (among many other checks) to make sure it meets a required level of accuracy.

While the existing heuristics engine has worked very well for us, as bots evolved we needed the flexibility to write increasingly complex rules. Unfortunately, such rules were not easily supported in the old engine. Customers have also been asking for more details about which specific heuristic caught a request, and for the flexibility to enforce different policies per heuristic ID.  We found that by building a new heuristics framework integrated into the Cloudflare Ruleset Engine, we could build a more flexible system to write rules and give Bot Management customers the granular explainability and control they were asking for. 

In our previous heuristics engine, we wrote rules in Lua as part of our openresty-based reverse proxy. The Lua-based engine was limited to a very small number of characteristics in a rule because of the high engineering cost we observed with adding more complexity.

With Lua, we would write fairly simple logic to match on specific characteristics of a request (i.e. user agent). Creating new heuristics of an existing class was fairly straight forward. All we’d need to do is define another instance of the existing class in our database. However, if we observed malicious traffic that required more than two characteristics (as a simple example, user-agent and ASN) to identify, we’d need to create bespoke logic for detections. Because our Lua heuristics engine was bundled with the code that ran ML models and other important logic, all changes had to go through the same review and release process. If we identified malicious traffic that needed a new heuristic class, and we were also blocked by pending changes in the codebase, we’d be forced to either wait or rollback the changes. If we’re writing a new rule for an “under attack” scenario, every extra minute it takes to deploy a new rule can mean an unacceptable impact to our customer’s business. 

More critical than time to deploy is the complexity that the heuristics engine supports. The old heuristics engine only supported using specific request attributes when creating a new rule. As bots became more sophisticated, we found we had to reject an increasing number of new heuristic candidates because we weren’t able to write precise enough rules. For example, we found a Golang TLS fingerprint frequently used by bots and by a small number of corporate VPNs. We couldn’t block the bots without also stopping the legitimate VPN usage as well, because the old heuristics platform lacked the flexibility to quickly compile sufficiently nuanced rules. Luckily, we already had the perfect solution with Cloudflare Ruleset Engine. 

The Ruleset Engine is familiar to anyone who has written a WAF rule, Load Balancing rule, or Transform rule, just to name a few. For Bot Management, the Wireshark-inspired syntax allows us to quickly write heuristics with much greater flexibility to vastly improve accuracy. We can write a rule in YAML that includes arbitrary sub-conditions and inherit the same framework the WAF team uses to both ensure any new rule undergoes a rigorous testing process with the ability to rapidly release new rules to stop attacks in real-time. 

Writing heuristics on the Cloudflare Ruleset Engine allows our engineers and analysts to write new rules in an easy to understand YAML syntax. This is critical to supporting a rapid response in under attack scenarios, especially as we support greater rule complexity. Here’s a simple rule using the new engine, to detect empty user-agents restricted to a specific JA4 fingerprint (right), compared to the empty user-agent detection in the old Lua based system (left): 

The Golang heuristic that captured corporate proxy traffic as well (mentioned above) was one of the first to migrate to the new Ruleset engine. Before the migration, traffic matching on this heuristic had a false positive rate of 0.01%. While that sounds like a very small number, this means for every million bots we block, 100 real users saw a Cloudflare challenge page unnecessarily. At Cloudflare scale, even small issues can have real, negative impact.

When we analyzed the traffic caught by this heuristic rule in depth, we saw the vast majority of attack traffic came from a small number of abusive networks. After narrowing the definition of the heuristic to flag the Golang fingerprint only when it’s sourced by the abusive networks, the rule now has a false positive rate of 0.0001% (One out of 1 million).  Updating the heuristic to include the network context improved our accuracy, while still blocking millions of bots every week and giving us plenty of training data for our bot detection models. Because this heuristic is now more accurate, newer ML models make more accurate decisions on what’s a bot and what isn’t.

While the new heuristics engine provides more accurate detections for all customers and a better experience for our analysts, moving to the Cloudflare Ruleset Engine also allows us to deliver new functionality for Enterprise Bot Management customers, specifically by offering more visibility. This new visibility is via a new field for Bot Management customers called Bot Detection IDs. Every heuristic we use includes a unique Bot Detection ID. These are visible to Bot Management customers in analytics, logs, and firewall events, and they can be used in the firewall to write precise rules for individual bots. 

Detections also include a specific tag describing the class of heuristic. Customers see these plotted over time in their analytics.

To illustrate how this data can help give customers visibility into why we blocked a request, here’s an example request flagged by Bot Management (with the IP address, ASN, and country changed):

Before, just seeing that our heuristics gave the request a score of 1 was not very helpful in understanding why it was flagged as a bot. Adding our Detection IDs to Firewall Events helps to paint a better picture for customers that we’ve identified this request as a bot because that traffic used an empty user-agent.

In addition to Analytics and Firewall Events, Bot Detection IDs are now available for Bot Management customers to use in Custom Rules, Rate Limiting Rules, Transform Rules, and Workers. 

One way we’re focused on improving Bot Management for our customers is by surfacing more attack-specific detections. During Birthday Week, we launched Leaked Credentials Check for all customers so that security teams could help prevent account takeover (ATO) attacks by identifying accounts at risk due to leaked credentials. We’ve now added two more detections that can help Bot Management enterprise customers identify suspicious login activity via specific detection IDs that monitor login attempts and failures on the zone. These detection IDs are not currently affecting the bot score, but will begin to later in 2025. Already, they can help many customers detect more account takeover events now.

Detection ID 201326592 monitors traffic on a customer website and looks for an anomalous rise in login failures (usually associated with brute force attacks), and ID 201326593 looks for an anomalous rise in login attempts (usually associated with credential stuffing). 

If you are a Bot Management customer, log in and head over to the Cloudflare dashboard and take a look in Security Analytics for bot detection IDs 201326592 and 201326593.

These will highlight ATO attempts targeting your site. If you spot anything suspicious, or would like to be protected against future attacks, create a rule that uses these detections to keep your application safe.

To support both business continuity and security needs, “security must evolve from being reactive to predictive”. Maintaining a healthy security posture entails monitoring and strengthening your security defenses to identify risks, ensure compliance, and protect against evolving threats. With our newest capabilities, you can now use Cloudflare to achieve a healthy posture across your SaaS and web applications. This addresses any security team’s ultimate (daily) question: How well are our assets and documents protected?

A predictive security posture relies on the following key components:

• Real-time discovery and inventory of all your assets and documents

• Continuous asset-aware threat detection and risk assessment

• Prioritised remediation suggestions to increase your protection

Today, we are sharing how we have built these key components across SaaS and web applications, and how you can use them to manage your business’s security posture.

Regardless of the applications you have connected to Cloudflare’s global network, Cloudflare actively scans for risks and misconfigurations associated with each one of them on a regular cadence. Identified risks and misconfigurations are surfaced in the dashboard under Security Center as insights.

Insights are grouped by their severity, type of risks, and corresponding Cloudflare solution, providing various angles for you to zoom in to what you want to focus on. When applicable, a one-click resolution is provided for selected insight types, such as setting minimum TLS version to 1.2 which is recommended by PCI DSS. This simplicity is highly appreciated by customers that are managing a growing set of assets being deployed across the organization.

To help shorten the time to resolution even further, we have recently added role-based access control (RBAC) to Security Insights in the Cloudflare dashboard. Now for individual security practitioners, they have access to a distilled view of the insights that are relevant for their role. A user with an administrator role (a CSO, for example) has access to, and visibility into, all insights.

In addition to account-wide Security Insights, we also provide posture overviews that are closer to the corresponding security configurations of your SaaS and web applications. Let’s dive into each of them.

Without centralized posture management, SaaS applications can feel like the security wild west. They contain a wealth of sensitive information – files, databases, workspaces, designs, invoices, or anything your company needs to operate, but control is limited to the vendor’s settings, leaving you with less visibility and fewer customization options. Moreover, team members are constantly creating, updating, and deleting content that can cause configuration drift and data exposure, such as sharing files publicly, adding PII to non-compliant databases, or giving access to third party integrations. With Cloudflare, you have visibility across your SaaS application fleet in one dashboard.

From the account-wide Security Insights, you can review insights for potential SaaS security issues:

You can choose to dig further with Cloud Access Security Broker (CASB) for a thorough review of the misconfigurations, risks, and failures to meet best practices across your SaaS fleet. You can identify a wealth of security information including, but not limited to:

• Publicly available or externally shared files

• Third-party applications with read or edit access

• Unknown or anonymous user access

• Databases with exposed credentials

• Users without two-factor authentication

• Inactive user accounts

You can also explore the Posture Findings page, which provides easy searching and navigation across documents that are stored within the SaaS applications.

Additionally, you can create policies to prevent configuration drift in your environment. Prevention-based policies help maintain a secure configuration and compliance standards, while reducing alert fatigue for Security Operations teams, and these policies can prevent the inappropriate movement or exfiltration of sensitive data. Unifying controls and visibility across environments makes it easier to lock down regulated data classes, maintain detailed audit trails via logs, and improve your security posture to reduce the risk of breaches.

Delivering SaaS security posture information to our customers requires collecting vast amounts of data from a wide range of platforms. In order to ensure that all the documents living in your SaaS apps (files, designs, etc.) are secure, we need to collect information about their configuration — are they publicly shared, do third-party apps have access, is multi-factor authentication (MFA) enabled? 

We previously did this with crawlers, which would pull data from the SaaS APIs. However, we were plagued with rate limits from the SaaS vendors when working with larger datasets. This forced us to work in batches and ramp scanning up and down as the vendors permitted. This led to stale findings and would make remediation cumbersome and unclear – for example, Cloudflare would be reporting that a file is still shared publicly for a short period after the permissions were removed, leading to customer confusion.

To fix this, we upgraded our data collection pipeline to be dynamic and real-time, reacting to changes in your environment as they occur, whether it’s a new security finding, an updated asset, or a critical alert from a vendor. We started with our Microsoft asset discovery and posture findings, providing you real-time insight into your Microsoft Admin Center, OneDrive, Outlook, and SharePoint configurations. We will be rapidly expanding support to additional SaaS vendors going forward.

Cloudflare Workers serve as the entry point for vendor webhooks, handling asset change notifications from external services. The workflow unfolds as follows:

• Webhook listener: An initial Worker acts as the webhook listener, receiving asset change messages from vendors.

• Data storage & queuing: Upon receiving a message, the Worker uploads the raw payload of the change notification to Cloudflare R2 for persistence, and publishes it to a Cloudflare Queue dedicated to raw asset changes.

• Transformation Worker: A second Worker, bound as a consumer to the raw asset change queue, processes the incoming messages. This Worker transforms the raw vendor-specific data into a generic format suitable for CASB. The transformed data is then:

  • Stored in Cloudflare R2 for future reference.

  • Published on another Cloudflare Queue, designated for transformed messages.

Once the transformed messages reach the CASB layer, they undergo further processing:

• Polling consumer: CASB has a consumer that polls the transformed message queue. Upon receiving a message, it determines the relevant handler required for processing.

• Crawler execution: The handler then maps the message to an appropriate crawler, which interacts with the vendor API to fetch the most up-to-date asset details.

• Data storage: The retrieved asset data is stored in the CASB database, ensuring it is accessible for security and compliance checks.

With this improvement, we are now processing 10 to 20 Microsoft updates per second, or 864,000 to 1.72 million updates daily, giving customers incredibly fast visibility into their environment. Look out for expansion to other SaaS vendors in the coming months. 

A unique challenge of securing web applications is that no one size fits all. An asset-aware posture management bridges the gap between a universal security solution and unique business needs, offering tailored recommendations for security teams to protect what matters.

Starting today, all Cloudflare customers have access to Security Overview, a new landing page customized for each of your onboarded domains. This page aggregates and prioritizes security suggestions across all your web applications:

1. Any (ongoing) attacks detected that require immediate attention

2. Disposition (mitigated, served by Cloudflare, served by origin) of all proxied traffic over the last 7 days

3. Summary of currently active security modules that are detecting threats

4. Suggestions of how to improve your security posture with a step-by-step guide

5. And a glimpse of your most active and lately updated security rules

These tailored security suggestions are surfaced based on your traffic profile and business needs, which is made possible by discovering your proxied web assets.

Many web applications, regardless of their industry or use case, require similar functionality: user identification, accepting payment information, etc. By discovering the assets serving this functionality, we can build and run targeted threat detection to protect them in depth.

As an example, bot traffic towards marketing pages versus login pages have different business impacts. Content scraping may be happening targeting your marketing materials, which you may or may not want to allow, while credential stuffing on your login page deserves immediate attention.

Web assets are described by a list of endpoints; and labelling each of them defines their business goals. A simple example can be POST requests to path /portal/login, which likely describes an API for user authentication. While the GET requests to path /portal/login denote the actual login webpage.

To describe business goals of endpoints, labels come into play. POST requests to the /portal/login endpoint serving end users and to the /api/admin/login endpoint used by employees can both can be labelled using the same cf-log-in managed label, letting Cloudflare know that usernames and passwords would be expected to be sent to these endpoints.

API Shield customers can already make use of endpoint labelling. In early Q2 2025, we are adding label discovery and suggestion capabilities, starting with three labels, cf-log-in, cf-sign-up, and cf-rss-feed. All other customers can manually add these labels to the saved endpoints. One example, explained below, is preventing disposable emails from being used during sign-ups. 

Customers told us that, with the growing excitement around generative AI, they need support to secure this new technology while not hindering innovation. Being able to discover LLM-powered services allows fine-tuning security controls that are relevant for this particular technology, such as inspecting prompts, limit prompting rates based on token usage, etc. In a separate Security Week blog post, we will share how we build Cloudflare Firewall for AI, and how you can easily protect your generative AI workloads.

Account fraud detection, which encompasses multiple attack vectors, is another key area that we are focusing on in 2025.

On many login and signup pages, a CAPTCHA solution is commonly used to only allow human beings through, assuming only bots perform undesirable actions. Put aside that most visual CAPTCHA puzzles can be easily solved by AI nowadays, such an approach cannot effectively solve the root cause of most account fraud vectors. For example, human beings using disposable emails to sign up single-use accounts to take advantage of signup promotions.

To solve this fraudulent sign up issue, a security rule currently under development could be deployed as below to block all attempts that use disposable emails as a user identifier, regardless of whether the requester was automated or not. All existing or future cf-log-in and cf-sign-up labelled endpoints are protected by this single rule, as they both require user identification.

Our fast expanding use-case driven threat detections are all running by default, from the first moment you onboarded your traffic to Cloudflare. The instant available detection results can be reviewed through security analytics, helping you make swift informed decisions.

APIs have their own set of risks and vulnerabilities, and today Cloudflare is delivering seven new risk scans through API Posture Management. This new capability of API Shield helps reduce risk by identifying security issues and fixing them early, before APIs are attacked. Because APIs are typically made up of many different backend services, security teams need to pinpoint which backend service is vulnerable so that development teams may remediate the identified issues.

Our new API posture management risk scans do exactly that: users can quickly identify which API endpoints are at risk to a number of vulnerabilities, including sensitive data exposure, authentication status, Broken Object Level Authorization (BOLA) attacks, and more.

Authentication Posture is one risk scan you’ll see in the new system. We focused on it to start with because sensitive data is at risk when API authentication is assumed to be enforced but is actually broken. Authentication Posture helps customers identify authentication misconfigurations for APIs and alerts of their presence. This is achieved by scanning for successful requests against the API and noting their authentication status. API Shield scans traffic daily and labels API endpoints that have missing and mixed authentication for further review.

For customers that have configured session IDs in API Shield, you can find the new risk scan labels and authentication details per endpoint in API Shield. Security teams can take this detail to their development teams to fix the broken authentication.

We’re launching today with scans for authentication posture, sensitive data, underprotected APIs, BOLA attacks, and anomaly scanning for API performance across errors, latency, and response size.

Achieving a good security posture in a fast-moving environment requires innovative solutions that can transform complexity into simplicity. Bringing together the ability to continuously assess threats and risks across both public and private IT environments through a single platform is our first step in supporting our customers’ efforts to maintain a healthy security posture.

To further enhance the relevance of security insights and suggestions provided and help you better prioritize your actions, we are looking into integrating Cloudflare’s global view of threat landscapes. With this, you gain additional perspectives, such as what the biggest threats to your industry are, and what attackers are targeting at the current moment. Stay tuned for more updates later this year.

If you haven’t done so yet, onboard your SaaS and web applications to Cloudflare today to gain instant insights into how to improve your business’s security posture.

Grinch Bots are still stealing Christmas

Back in 2021, we covered the antics of Grinch Bots and how the combination of proposed regulation and technology could prevent these malicious programs from stealing holiday cheer.

Fast-forward to 2024 — the Stop Grinch Bots Act of 2021 has not passed, and bots are more active and powerful than ever, leaving businesses to fend off increasingly sophisticated attacks on their own. During Black Friday 2024, Cloudflare observed:

• 29% of all traffic on Black Friday was Grinch Bots. Humans still accounted for the majority of all traffic, but bot traffic was up 4x from three years ago in absolute terms. 

• 1% of traffic on Black Friday came from AI bots. The majority of it came from Claude, Meta, and Amazon. 71% of this traffic was given the green light to access the content requested. 

• 63% of login attempts across our network on Black Friday were from bots. While this number is high, it was down a few percentage points compared to a month prior, indicating that more humans accessed their accounts and holiday deals. 

• Human logins on e-commerce sites increased 7-8% compared to the previous month. 

These days, holiday shopping doesn’t start on Black Friday and stop on Cyber Monday. Instead, it stretches through Cyber Week and beyond, including flash sales, pre-orders, and various other promotions. While this provides consumers more opportunities to shop, it also creates more openings for Grinch Bots to wreak havoc.

Black Friday and Cyber Monday in 2024 brought record-breaking shopping — and grinching. In addition to looking across our entire network, we also analyzed traffic patterns specifically on a cohort of e-commerce sites. 

Legitimate shoppers flocked to e-commerce sites, with requests reaching an astounding 405 billion on Black Friday, accounting for 81% of the day’s total traffic to e-commerce sites. Retailers reaped the rewards of their deals and advertising, seeing a 50% surge in shoppers week-over-week and a 61% increase compared to the previous month.

Unfortunately, Grinch Bots were equally active. Total e-commerce bot activity surged to 103 billion requests, representing up to 19% of all traffic to e-commerce sites. Nearly one in every five requests to an online store was not a real customer. That’s a lot of resources to waste on bogus traffic. Cyber Week was a battleground, with bots hoarding inventory, exploiting deals, and disrupting genuine shopping experiences.

The upside, if there is one, is that there was more human activity on e-commerce sites (81%) than observed on our network more broadly (71%). 

Cloudflare saw 4x more bot requests than what we observed in 2021. Being able to observe and score all this traffic at scale means we can help customers keep the grinches away. We also got to see patterns that help us better identify the concentration of these attacks: 

• 19% of traffic on e-commerce sites was Grinch Bots

• 1% of traffic to e-commerce sites was from AI Bots. 

• 63% of login attempt requests across our network were from bots 

• 22% of bot activity originated from residential proxy networks

What are all of these bots up to? 

This year marked a breakthrough for AI-driven bots, agents, and models, with their impact spilling into Black Friday. AI bots went from zero to one, now making up 1% of all bot traffic on e-commerce sites. 

AI-driven bots generated 29 billion requests on Black Friday alone, with Meta-external, Claudebot, and Amazonbot leading the pack. Based on their owners, these bots are meant to crawl to augment training data sets for Llama, Claude, and Alexa respectively. 

We looked at e-commerce sites specifically to find out if these bots were treating all content equally. While Meta-External and Amazonbot were still in the Top 3 of AI bots reaching e-commerce sites, Bytedance’s Bytespider crawled the most shopping sites.

In addition to scraping, crawling, and shopping, bots also targeted customer accounts on Black Friday. We saw 14.1 billion requests from bots to /login endpoints, accounting for 63% of that day’s login attempts. 

While this number seems high, intuitively it makes sense, given that humans don’t log in to accounts every day, but bots definitely try to crack accounts every day. Interestingly, while humans only accounted for 36% of traffic to login pages on Black Friday, this number was up 7-8% compared to the prior month. This suggests that more shoppers logged in to capitalize on deals and discounts on Black Friday than in preceding weeks. Human logins peaked at around 40% of all traffic to login sites on the Monday before Thanksgiving, and again on Cyber Monday.  

Separately, we also saw a 37% increase in leaked passwords used in login requests compared to the prior month. During Birthday Week, we shared how 65% of internet users are at risk of ATO due to re-use of leaked passwords. This surge, coinciding with heightened human and bot traffic, underscores a troubling pattern: both humans and bots continue to depend on common and compromised passwords, amplifying security risks.

Proxy bots: Regardless of whether they’re crawling your content or hoarding your wares, 22% of bot traffic originated from residential proxy networks. This obfuscation makes these requests look like legitimate customers browsing from their homes rather than large cloud networks. The large pool of IP addresses and the diversity of networks poses a challenge to traditional bot defense mechanisms that rely on IP reputation and rate limiting. 

Moreover, the diversity of IP addresses enables the attackers to rotate through them indefinitely. This shrinks the window of opportunity for bot detection systems to effectively detect and stop the attacks. The use of residential proxies is a trend we have been tracking for months now and Black Friday traffic was within the range we’ve seen throughout this year.

If you’re using Cloudflare’s Bot Management, your site is already protected from these bots since we update our bot score based on these types of network fingerprints. In May 2024, we introduced our latest model optimized for detecting residential proxies. Early results show promising declines in this type of activity, indicating that bot operators may be reducing their reliance on residential proxies. 

35% of all traffic on Black Friday was Grinch Bots. To keep Grinch Bots at bay, businesses need year-round bot protection and proactive strategies tailored to the unique challenges of holiday shopping.

Here are 4 yules (aka “rules”) for the season:

(1) Block bots: 22% of bot traffic originated from residential proxy networks. Our bot management score automatically adjusts based on these network signals. Use our Bot Score in rules to challenge sensitive actions. 

(2) Monitor potential Account Takeover (ATO) attacks: Bots often test stolen credentials in the months leading up to Cyber Week to refine their strategies. Re-use of stolen credentials makes businesses even more vulnerable. Our account abuse detections help customers monitor login paths for leaked credentials and traffic anomalies.

Check out more examples of related rules you can create.

(3) Rate limit account and purchase paths: Apply rate-limiting best practices on critical application paths. These include limiting new account access/creation from previously seen IP addresses, and leveraging other network fingerprints, to help prevent promo code abuse and inventory hoarding, as well as identifying account takeover attempts through the application of detection IDs and leaked credential checks.

(4) Block AI bots abusing shopping features to maintain fair access for human users. If you’re using Cloudflare, you can quickly block all AI bots by enabling our automatic AI bot blocking feature.  

Over the next year, e-commerce sites should expect to see more humans shopping for longer periods. As sale periods lengthen (like they did in 2024) we expect more peaks in human activity on e-commerce sites across November and December. This is great for consumers and great for merchants.

More AI bots and agents will be integrated into e-commerce journeys in 2025. AI bots will not only be crawling sites for training data, but will also integrate into the shopping experience. AI bots did not exist in 2021, but now make up 1% of all bot traffic. This is only the tip of the iceberg and their growth will explode in the next year. We expect this to pose new risks as bots mimic and act on behalf of humans.

More sophisticated automation through network, device, and cookie cycling will also become a bigger threat. Bot operators will continue to employ advanced evasion tactics like rotating devices, IP addresses, and cookies to bypass detection.

Grinch Bots are evolving, and regulation may be slowing, but businesses don’t have to face them alone. We remain resolute in our mission to help build a better Internet ... and holiday shopping experience.

Even though the holiday season is closing out soon, bots are never on vacation. It’s never too late or too early to start protecting your customers and your business from grinches that work all year round.

Wishing you all happy holidays and a bot-free new year!

We’re excited to announce that we’re going to be adding SSL.com as a certificate authority that Cloudflare customers can use. This means that Cloudflare customers that are currently relying on Entrust as a CA and uploading their certificate manually to Cloudflare will now be able to rely on Cloudflare’s certificate management pipeline for automatic issuance and renewal of SSL.com certificates. 

With great power comes great responsibility Every publicly trusted certificate authority (CA) is responsible for maintaining a high standard of security and compliance to ensure that the certificates they issue are trustworthy. The security of millions of websites and applications relies on a CA’s commitment to these standards, which are set by the CA/Browser Forum, the governing body that defines the baseline requirements for certificate authorities. These standards include rules regarding certificate issuance, validation, and revocation, all designed to secure the data transferred over the Internet. 

However, as with all complex software systems, it’s inevitable that bugs or issues may arise, leading to the mis-issuance of certificates. Improperly issued certificates pose a significant risk to Internet security, as they can be exploited by malicious actors to impersonate legitimate websites and intercept sensitive data. 

To mitigate such risk, publicly trusted CAs are required to communicate issues as soon as they are discovered, so that domain owners can replace the compromised certificates immediately. Once the issue is communicated, CAs must revoke the mis-issued certificates within 5 days to signal to browsers and clients that the compromised certificate should no longer be trusted. This level of transparency and urgency around the revocation process is essential for minimizing the risk posed by compromised certificates. 

Why Chrome and Mozilla are distrusting Entrust The decision made by Chrome and Mozilla to distrust Entrust’s public TLS certificates stems from concerns regarding Entrust’s incident response and remediation process. In several instances, Entrust failed to report critical issues and did not revoke certificates in a timely manner. The pattern of delayed action has eroded the browsers’ confidence in Entrust’s ability to act quickly and transparently, which is crucial for maintaining trust as a CA. 

Google and Mozilla cited the ongoing lack of transparency and urgency in addressing mis-issuances as the primary reason for their distrust decision. Google specifically pointed out that over the past 6 years, Entrust has shown a "pattern of compliance failures" and failed to make the "tangible, measurable progress" necessary to restore trust. Mozilla echoed these concerns, emphasizing the importance of holding Entrust accountable to ensure the integrity and security of the public Internet. 

Entrust’s response to the distrust announcement  In response to the distrust announcement from Chrome and Mozilla, Entrust has taken proactive steps to ensure continuity for their customers. To prevent service disruption, Entrust has announced that they are partnering with SSL.com, a CA that’s trusted by all major browsers, including Chrome and Mozilla, to issue certificates for their customers. By issuing certificates from SSL.com’s roots, Entrust aims to provide a seamless transition for their customers, ensuring that they can continue to obtain certificates that are recognized and trusted by the browsers their users rely on. 

In addition to their partnership with SSL.com, Entrust stated that they are working on a number of improvements, including changes to their organizational structure, revisions to their incident response process and policies, and a push towards automation to ensure compliant certificate issuances. 

Now available: SSL.com as a certificate authority for Advanced Certificate Manager and SSL for SaaS certificates We’re excited to announce that customers using Advanced Certificate Manager will now be able to select SSL.com as a certificate authority for Advanced certificates and Total TLS certificates. Once the certificate is issued, Cloudflare will handle all future renewals on your behalf. 

By default, Cloudflare will issue SSL.com certificates with a 90 day validity period. However, customers using Advanced Certificate Manager will have the option to set a custom validity period (14, 30, or 90 days) for their SSL.com certificates. In addition, Enterprise customers will have the option to obtain 1-year SSL.com certificates. Every SSL.com certificate order will include 1 RSA and 1 ECDSA certificate.

Note: We are gradually rolling this out and customers should see the CA become available to them through the end of September and into October. 

If you’re using Cloudflare as your DNS provider, there are no additional steps for you to take to get the certificate issued. Cloudflare will validate the ownership of the domain on your behalf to get your SSL.com certificate issued and renewed. 

If you’re using an external DNS provider and have wildcard hostnames on your certificates, DNS based validation will need to be used, which means that you’ll need to add TXT DCV tokens at your DNS provider in order to get the certificate issued. With SSL.com, two tokens are returned for every hostname on the certificate. This is because SSL.com uses different tokens for the RSA and ECDSA certificates. To reduce the overhead around certificate management, we recommend setting up DCV Delegation to allow Cloudflare to place domain control validation (DCV) tokens on your behalf. Once DCV Delegation is set up, Cloudflare will automatically issue, renew, and deploy all future certificates for you. 

Advanced Certificates: selecting SSL.com as a CA through the UI or API Customers can select SSL.com as a CA through the UI or through the Advanced Certificate API endpoint by specifying “ssl_com” in the certificate_authority parameter. 

If you’d like to use SSL.com as a CA for an advanced certificate, you can select “SSL.com” as your CA when creating a new Advanced certificate order. 

If you’d like to use SSL.com as a CA for all of your certificates, we recommend setting your Total TLS CA to SSL.com. This will issue an individual certificate for each of your proxied hostname from the CA. 

Note: Total TLS is a feature that’s only available to customers that are using Cloudflare as their DNS provider. 

SSL for SaaS: selecting SSL.com as a CA through the UI or API Enterprise customers can select SSL.com as a CA through the custom hostname creation UI or through the Custom Hostnames API endpoint by specifying “ssl_com” in the certificate_authority parameter. 

All custom hostname certificates issued from SSL.com will have a 90 day validity period. If you have wildcard support enabled for custom hostnames, we recommend using DCV Delegation to ensure that all certificate issuances and renewals are automatic.  

Cloudflare customers that use Entrust as their CA are required to manually handle all certificate issuances and renewals. Since Cloudflare does not directly integrate with Entrust, customers have to get their certificates issued directly from the CA and upload them to Cloudflare as custom certificates. Once these certificates come up for renewal, customers have to repeat this manual process and upload the renewed certificates to Cloudflare before the expiration date. 

Manually managing your certificate’s lifecycle is a time-consuming and error prone process. With certificate lifetimes decreasing from 1 year to 90 days, this cycle needs to be repeated more frequently by the domain owner. 

As Entrust transitions to issuing certificates from SSL.com roots, this manual management process will remain unless customers switch to Cloudflare’s managed certificate pipeline. By making this switch, you can continue to receive SSL.com certificates without the hassle of manual management — Cloudflare will handle all issuances and renewals for you!

In early October, we will be reaching out to customers who have uploaded Entrust certificates to Cloudflare to recommend migrating to our managed pipeline for SSL.com certificate issuances, simplifying your certificate management process. 

If you’re ready to make the transition today, simply go to the SSL/TLS tab in your Cloudflare dashboard, click “Order Advanced Certificate”, and select “SSL.com” as your certificate authority. Once your new SSL.com certificate is issued, you can either remove your Entrust certificate or simply let it expire. Cloudflare will seamlessly transition to serving the managed SSL.com certificate before the Entrust certificate expires, ensuring zero downtime during the switch. 

Over the last twelve months, the Internet security landscape has changed dramatically. Geopolitical uncertainty, coupled with an active 2024 voting season in many countries across the world, has led to a substantial increase in malicious traffic activity across the Internet. In this report, we take a look at Cloudflare’s perspective on Internet application security.

This report is the fourth edition of our Application Security Report and is an official update to our Q2 2023 report. New in this report is a section focused on client-side security within the context of web applications.

Throughout the report we discuss various insights. From a global standpoint, mitigated traffic across the whole network now averages 7%, and WAF and Bot mitigations are the source of over half of that. While DDoS attacks remain the number one attack vector used against web applications, targeted CVE attacks are also worth keeping an eye on, as we have seen exploits as fast as 22 minutes after a proof of concept was released.

Focusing on bots, about a third of all traffic we observe is automated, and of that, the vast majority (93%) is not generated by bots in Cloudflare’s verified list and is potentially malicious.

API traffic is also still growing, now accounting for 60% of all traffic, and maybe more concerning, is that organizations have up to a quarter of their API endpoints not accounted for.

We also touch on client side security and the proliferation of third-party integrations in web applications. On average, enterprise sites integrate 47 third-party endpoints according to Page Shield data.

It is also worth mentioning that since the last report, our network, from which we gather the data and insights, is bigger and faster: we are now processing an average of 57 million HTTP requests/second (+23.9% YoY) and 77 million at peak (+22.2% YoY). From a DNS perspective, we are handling 35 million DNS queries per second (+40% YoY). This is the sum of authoritative and resolver requests served by our infrastructure.

Maybe even more noteworthy, is that, focusing on HTTP requests only, in Q1 2024 Cloudflare blocked an average of 209 billion cyber threats each day (+86.6% YoY). That is a substantial increase in relative terms compared to the same time last year.

As usual, before we dive in, we need to define our terms.

Throughout this report, we will refer to the following terms:

• Mitigated traffic: any eyeball HTTP* request that had a “terminating” action applied to it by the Cloudflare platform. These include the following actions: BLOCK, CHALLENGE, JS_CHALLENGE and MANAGED_CHALLENGE. This does not include requests that had the following actions applied: LOG, SKIP, ALLOW. They also accounted for a relatively small percentage of requests. Additionally, we improved our calculation regarding the CHALLENGE type actions to ensure that only unsolved challenges are counted as mitigated. A detailed description of actions can be found in our developer documentation. This has not changed from last year’s report.

• Bot traffic/automated traffic: any HTTP* request identified by Cloudflare’s Bot Management system as being generated by a bot. This includes requests with a bot score between 1 and 29 inclusive. This has not changed from last year’s report.

• API traffic: any HTTP* request with a response content type of XML or JSON. Where the response content type is not available, such as for mitigated requests, the equivalent Accept content type (specified by the user agent) is used instead. In this latter case, API traffic won’t be fully accounted for, but it still provides a good representation for the purposes of gaining insights. This has not changed from last year’s report.

Unless otherwise stated, the time frame evaluated in this post is the period from April 1, 2023, through March 31, 2024, inclusive.

Finally, please note that the data is calculated based only on traffic observed across the Cloudflare network and does not necessarily represent overall HTTP traffic patterns across the Internet.

^{*When referring to HTTP traffic we mean both HTTP and HTTPS.}

Compared to the prior 12-month period, Cloudflare mitigated a higher percentage of application layer traffic and layer 7 (L7) DDoS attacks between Q2 2023 and Q1 2024, growing from 6% to 6.8%.

Figure 1: Percent of mitigated HTTP traffic increasing over the last 12 months

During large global attack events, we can observe spikes of mitigated traffic approaching 12% of all HTTP traffic. These are much larger spikes than we have ever observed across our entire network.

As the Cloudflare platform continues to expose additional signals to identify potentially malicious traffic, customers have been actively using these signals in WAF Custom Rules to improve their security posture. Example signals include our WAF Attack Score, which identifies malicious payloads, and our Bot Score, which identifies automated traffic.

After WAF and Bot mitigations, HTTP DDoS rules are the second-largest contributor to mitigated traffic. IP reputation, that uses our IP threat score to block traffic, and access rules, which are simply IP and country blocks, follow in third and fourth place.

Figure 2: Mitigated traffic by Cloudflare product group

Zero-day exploits (also called zero-day threats) are increasing, as is the speed of weaponization of disclosed CVEs. In 2023, 97 zero-days were exploited in the wild, and that’s along with a 15% increase of disclosed CVEs between 2022 and 2023.

Looking at CVE exploitation attempts against customers, Cloudflare mostly observed scanning activity, followed by command injections, and some exploitation attempts of vulnerabilities that had PoCs available online, including Apache CVE-2023-50164 and CVE-2022-33891, Coldfusion CVE-2023-29298 CVE-2023-38203 and CVE-2023-26360, and MobileIron CVE-2023-35082.

This trend in CVE exploitation attempt activity indicates that attackers are going for the easiest targets first, and likely having success in some instances given the continued activity around old vulnerabilities.

As just one example, Cloudflare observed exploitation attempts of CVE-2024-27198 (JetBrains TeamCity authentication bypass) at 19:45 UTC on March 4, just 22 minutes after proof-of-concept code was published.

Figure 3: JetBrains TeamCity authentication bypass timeline

The speed of exploitation of disclosed CVEs is often quicker than the speed at which humans can create WAF rules or create and deploy patches to mitigate attacks. This also applies to our own internal security analyst team that maintains the WAF Managed Ruleset, which has led us to combine the human written signatures with an ML-based approach to achieve the best balance between low false positives and speed of response.

CVE exploitation campaigns from specific threat actors are clearly visible when we focus on a subset of CVE categories. For example, if we filter on CVEs that result in remote code execution (RCE), we see clear attempts to exploit Apache and Adobe installations towards the end of 2023 and start of 2024 along with a notable campaign targeting Citrix in May of this year.

Figure 4: Worldwide daily number of requests for Code Execution CVEs

Similar views become clearly visible when focusing on other CVEs or specific attack categories.

DDoS attacks remain the most common attack type against web applications, with DDoS comprising 37.1% of all mitigated application traffic over the time period considered.

Figure 5: Volume of HTTP DDoS attacks over time

We saw a large increase in volumetric attacks in February and March 2024. This was partly the result of improved detections deployed by our teams, in addition to increased attack activity. In the first quarter of 2024 alone, Cloudflare’s automated defenses mitigated 4.5 million unique DDoS attacks, an amount equivalent to 32% of all the DDoS attacks Cloudflare mitigated in 2023. Specifically, application layer HTTP DDoS attacks increased by 93% YoY and 51% quarter-over-quarter (QoQ).

Cloudflare correlates DDoS attack traffic and defines unique attacks by looking at event start and end times along with target destination.

Motives for launching DDoS attacks range from targeting specific organizations for financial gains (ransom), to testing the capacity of botnets, to targeting institutions and countries for political reasons. As an example, Cloudflare observed a 466% increase in DDoS attacks on Sweden after its acceptance to the NATO alliance on March 7, 2024. This mirrored the DDoS pattern observed during Finland’s NATO acceptance in 2023. The size of DDoS attacks themselves are also increasing.

In August 2023, Cloudflare mitigated a hyper-volumetric HTTP/2 Rapid Reset DDoS attack that peaked at 201 million requests per second (rps) – three times larger than any previously observed attack. In the attack, threat actors exploited a zero-day vulnerability in the HTTP/2 protocol that had the potential to incapacitate nearly any server or application supporting HTTP/2. This underscores how menacing DDoS vulnerabilities are for unprotected organizations.

Gaming and gambling became the most targeted sector by DDoS attacks, followed by Internet technology companies and cryptomining.

Figure 6: Largest HTTP DDoS attacks as seen by Cloudflare, by year

Cloudflare has continued to invest heavily in our bot detection systems. In early July, we declared AIndependence to help preserve a safe Internet for content creators, offering a brand new “easy button” to block all AI bots. It’s available for all customers, including those on our free tier.

Major progress has also been made in other complementary systems such as our Turnstile offering, a user-friendly, privacy-preserving alternative to CAPTCHA.

All these systems and technologies help us better identify and differentiate human traffic from automated bot traffic.

31.2% of all application traffic processed by Cloudflare is bot traffic. This percentage has stayed relatively consistent (hovering at about 30%) over the past three years.

The term bot traffic may carry a negative connotation, but in reality bot traffic is not necessarily good or bad; it all depends on the purpose of the bots. Some are “good” and perform a needed service, such as customer service chatbots and authorized search engine crawlers. But some bots misuse an online product or service and need to be blocked.

Different application owners may have different criteria for what they deem a “bad” bot. For example, some organizations may want to block a content scraping bot that is being deployed by a competitor to undercut on prices, whereas an organization that does not sell products or services may not be as concerned with content scraping. Known, good bots are classified by Cloudflare as “verified bots.”

Unverified bots are often created for disruptive and harmful purposes, such as hoarding inventory, launching DDoS attacks, or attempting to take over an account via brute force or credential stuffing. Verified bots are those that are known to be safe, such as search engine crawlers, and Cloudflare aims to verify all major legitimate bot operators. A list of all verified bots can be found in our documentation.

Attackers leveraging bots focus most on industries that could bring them large financial gains. For example, consumer goods websites are often the target of inventory hoarding, price scraping run by competition or automated applications aimed at exploiting some sort of arbitrage (for example, sneaker bots). This type of abuse can have a significant financial impact on the target organization.

Figure 8: Industries with the highest median daily share of bot traffic

Consumers and end users expect dynamic web and mobile experiences powered by APIs. For businesses, APIs fuel competitive advantages, greater business intelligence, faster cloud deployments, integration of new AI capabilities, and more.

However, APIs introduce new risks by providing outside parties additional attack surfaces with which to access applications and databases which also need to be secured. As a consequence, numerous attacks we observe are now targeting API endpoints first rather than the traditional web interfaces.

The additional security concerns are of course not slowing down adoption of API first applications.

This is a two percentage point increase compared to last year’s report. Of this 60%, about 4% on average is mitigated by our security systems.

Figure 9: Share of mitigated API traffic

A substantial spike is visible around January 11-17 that accounts for almost a 10% increase in traffic share alone for that period. This was due to a specific customer zone receiving attack traffic that was mitigated by a WAF Custom Rule.

Digging into mitigation sources for API traffic, we see the WAF being the largest contributor, as standard malicious payloads are commonly applicable to both API endpoints and standard web applications.

Figure 10: API mitigated traffic broken down by product group

You cannot protect what you cannot see. And, many organizations lack accurate API inventories, even when they believe they can correctly identify API traffic.

Using our proprietary machine learning model that scans not just known API calls, but all HTTP requests (identifying API traffic that may be going unaccounted for), we found that organizations had 33% more public-facing API endpoints than they knew about. This number was the median, and it was calculated by comparing the number of API endpoints detected through machine learning based discovery vs. customer-provided session identifiers.

This suggests that nearly a quarter of APIs are “shadow APIs” and may not be properly inventoried and secured.

Most organizations’ web apps rely on separate programs or pieces of code from third-party providers (usually coded in JavaScript). The use of third-party scripts accelerates modern web app development and allows organizations to ship features to market faster, without having to build all new app features in-house.

Using Cloudflare's client side security product, Page Shield, we can get a view on the popularity of third party libraries used on the Internet and the risk they pose to organizations. This has become very relevant recently due to the Polyfill.io incident that affected more than one hundred thousand sites.

Cloudflare’s typical enterprise customer uses an average of 47 third-party scripts, and a median of 20 third-party scripts. The average is much higher than the median due to SaaS providers, who often have thousands of subdomains which may all use third-party scripts. Here are some of the top third-party script providers Cloudflare customers commonly use:

• Google (Tag Manager, Analytics, Ads, Translate, reCAPTCHA, YouTube)

• Meta (Facebook Pixel, Instagram)

• Cloudflare (Web Analytics)

• jsDelivr

• New Relic

• Appcues

• Microsoft (Clarity, Bing, LinkedIn)

• jQuery

• WordPress (Web Analytics, hosted plugins)

• Pinterest

• UNPKG

• TikTok

• Hotjar

While useful, third-party software dependencies are often loaded directly by the end-user’s browser (i.e. they are loaded client-side) placing organizations and their customers at risk given that organizations have no direct control over third-party security measures. For example, in the retail sector, 18% of all data breaches originate from Magecart style attacks, according to Verizon’s 2024 Data Breach Investigations Report.

Loading a third-party script into your website poses risks, even more so when that script “calls home” to submit data to perform the intended function. A typical example here is Google Analytics: whenever a user performs an action, the Google Analytics script will submit data back to the Google servers. We identify these as connections.

On average, each enterprise website connects to 50 separate third-party destinations, with a median of 15. Each of these connections also poses a potential client-side security risk as attackers will often use them to exfiltrate additional data going unnoticed.

Here are some of the top third-party connections Cloudflare customers commonly use:

• Google (Analytics, Ads)

• Microsoft (Clarity, Bing, LinkedIn)

• Meta (Facebook Pixel)

• Hotjar

• Kaspersky

• Sentry

• Criteo

• tawk.to

• OneTrust

• New Relic

• PayPal

This application security report is also available in PDF format with additional recommendations on how to address many of the concerns raised, along with additional insights.

We also publish many of our reports with dynamic charts on Cloudflare Radar, making it an excellent resource to keep up to date with the state of the Internet.

polyfill.io, a popular JavaScript library service, can no longer be trusted and should be removed from websites.

Multiple reports, corroborated with data seen by our own client-side security system, Page Shield, have shown that the polyfill service was being used, and could be used again, to inject malicious JavaScript code into users’ browsers. This is a real threat to the Internet at large given the popularity of this library.

We have, over the last 24 hours, released an automatic JavaScript URL rewriting service that will rewrite any link to polyfill.io found in a website proxied by Cloudflare to a link to our mirror under cdnjs. This will avoid breaking site functionality while mitigating the risk of a supply chain attack.

Any website on the free plan has this feature automatically activated now. Websites on any paid plan can turn on this feature with a single click.

You can find this new feature under Security ⇒ Settings on any zone using Cloudflare.

Contrary to what is stated on the polyfill.io website, Cloudflare has never recommended the polyfill.io service or authorized their use of Cloudflare’s name on their website. We have asked them to remove the false statement, and they have, so far, ignored our requests. This is yet another warning sign that they cannot be trusted.

If you are not using Cloudflare today, we still highly recommend that you remove any use of polyfill.io and/or find an alternative solution. And, while the automatic replacement function will handle most cases, the best practice is to remove polyfill.io from your projects and replace it with a secure alternative mirror like Cloudflare’s even if you are a customer.

You can do this by searching your code repositories for instances of polyfill.io and replacing it with cdnjs.cloudflare.com/polyfill/ (Cloudflare’s mirror). This is a non-breaking change as the two URLs will serve the same polyfill content. All website owners, regardless of the website using Cloudflare, should do this now.

Back in February, the domain polyfill.io, which hosts a popular JavaScript library, was sold to a new owner: Funnull, a relatively unknown company. At the time, we were concerned that this created a supply chain risk. This led us to spin up our own mirror of the polyfill.io code hosted under cdnjs, a JavaScript library repository sponsored by Cloudflare.

The new owner was unknown in the industry and did not have a track record of trust to administer a project such as polyfill.io. The concern, highlighted even by the original author, was that if they were to abuse polyfill.io by injecting additional code to the library, it could cause far-reaching security problems on the Internet affecting several hundreds of thousands websites. Or it could be used to perform a targeted supply-chain attack against specific websites.

Unfortunately, that worry came true on June 25, 2024, as the polyfill.io service was being used to inject nefarious code that, under certain circumstances, redirected users to other websites.

We have taken the exceptional step of using our ability to modify HTML on the fly to replace references to the polyfill.io CDN in our customers’ websites with links to our own, safe, mirror created back in February.

In the meantime, additional threat feed providers have also taken the decision to flag the domain as malicious. We have not outright blocked the domain through any of the mechanisms we have because we are concerned it could cause widespread web outages given how broadly polyfill.io is used with some estimates indicating usage on nearly 4% of all websites.

The original report indicates that malicious code was injected that, under certain circumstances, would redirect users to betting sites. It was doing this by loading additional JavaScript that would perform the redirect, under a set of additional domains which can be considered Indicators of Compromise (IoCs):

https://www.googie-anaiytics.com/analytics.js
https://www.googie-anaiytics.com/html/checkcachehw.js
https://www.googie-anaiytics.com/gtags.js
https://www.googie-anaiytics.com/keywords/vn-keyword.json
https://www.googie-anaiytics.com/webs-1.0.1.js
https://www.googie-anaiytics.com/analytics.js
https://www.googie-anaiytics.com/webs-1.0.2.js
https://www.googie-anaiytics.com/ga.js
https://www.googie-anaiytics.com/web-1.0.1.js
https://www.googie-anaiytics.com/web.js
https://www.googie-anaiytics.com/collect.js
https://kuurza.com/redirect?from=bitget

(note the intentional misspelling of Google Analytics)

Page Shield, our client side security solution, is available on all paid plans. When turned on, it collects information about JavaScript files loaded by end user browsers accessing your website.

By looking at the database of detected JavaScript files, we immediately found matches with the IoCs provided above starting as far back as 2024-06-08 15:23:51 (first seen timestamp on Page Shield detected JavaScript file). This was a clear indication that malicious activity was active and associated with polyfill.io.

To achieve performant HTML rewriting, we need to make blazing-fast HTML alterations as responses stream through Cloudflare’s network. This has been made possible by leveraging ROFL (Response Overseer for FL). ROFL powers various Cloudflare products that need to alter HTML as it streams, such as Cloudflare Fonts, Email Obfuscation and Rocket Loader

ROFL is developed entirely in Rust. The memory-safety features of Rust are indispensable for ensuring protection against memory leaks while processing a staggering volume of requests, measuring in the millions per second. Rust's compiled nature allows us to finely optimize our code for specific hardware configurations, delivering performance gains compared to interpreted languages.

The performance of ROFL allows us to rewrite HTML on-the-fly and modify the polyfill.io links quickly, safely, and efficiently. This speed helps us reduce any additional latency added by processing the HTML file.

If the feature is turned on, for any HTTP response with an HTML Content-Type, we parse all JavaScript script tag source attributes. If any are found linking to polyfill.io, we rewrite the src attribute to link to our mirror instead. We map to the correct version of the polyfill service while the query string is left untouched.

The logic will not activate if a Content Security Policy (CSP) header is found in the response. This ensures we don’t replace the link while breaking the CSP policy and therefore potentially breaking the website.

Cloudflare proxies millions of websites, and a large portion of these sites are on our free plan. Free plan customers tend to have simpler applications while not having the resources to update and react quickly to security concerns. We therefore decided to turn on the feature by default for sites on our free plan, as the likelihood of causing issues is reduced while also helping keep safe a very large portion of applications using polyfill.io.

Paid plan customers, on the other hand, have more complex applications and react quicker to security notices. We are confident that most paid customers using polyfill.io and Cloudflare will appreciate the ability to virtually patch the issue with a single click, while controlling when to do so.

All customers can turn off the feature at any time.

This isn’t the first time we’ve decided a security problem was so widespread and serious that we’d enable protection for all customers regardless of whether they were a paying customer or not. Back in 2014, we enabled Shellshock protection for everyone. In 2021, when the log4j vulnerability was disclosed we rolled out protection for all customers.

If you are using Cloudflare, you can remove polyfill.io with a single click on the Cloudflare dashboard by heading over to your zone ⇒ Security ⇒ Settings. If you are a free customer, the rewrite is automatically active. This feature, we hope, will help you quickly patch the issue.

Nonetheless, you should ultimately search your code repositories for instances of polyfill.io and replace them with an alternative provider, such as Cloudflare’s secure mirror under cdnjs (https://cdnjs.cloudflare.com/polyfill/). Website owners who are not using Cloudflare should also perform these steps.

The underlying bundle links you should use are:

For minified: https://cdnjs.cloudflare.com/polyfill/v3/polyfill.min.js For unminified: https://cdnjs.cloudflare.com/polyfill/v3/polyfill.js

Doing this ensures your website is no longer relying on polyfill.io.

Let’s Encrypt, a publicly trusted certificate authority (CA) that Cloudflare uses to issue TLS certificates, has been relying on two distinct certificate chains. One is cross-signed with IdenTrust, a globally trusted CA that has been around since 2000, and the other is Let’s Encrypt’s own root CA, ISRG Root X1. Since Let’s Encrypt launched, ISRG Root X1 has been steadily gaining its own device compatibility.

On September 30, 2024, Let’s Encrypt’s certificate chain cross-signed with IdenTrust will expire. To proactively prepare for this change, on May 15, 2024, Cloudflare will stop issuing certificates from the cross-signed chain and will instead use Let’s Encrypt’s ISRG Root X1 chain for all future Let’s Encrypt certificates.

The change in the certificate chain will impact legacy devices and systems, such as Android devices version 7.1.1 or older, as those exclusively rely on the cross-signed chain and lack the ISRG X1 root in their trust store. These clients may encounter TLS errors or warnings when accessing domains secured by a Let’s Encrypt certificate.

According to Let’s Encrypt, more than 93.9% of Android devices already trust the ISRG Root X1 and this number is expected to increase in 2024, especially as Android releases version 14, which makes the Android trust store easily and automatically upgradable.

We took a look at the data ourselves and found that, from all Android requests, 2.96% of them come from devices that will be affected by the change. In addition, only 1.13% of all requests from Firefox come from affected versions, which means that most (98.87%) of the requests coming from Android versions that are using Firefox will not be impacted.

If you’re worried about the change impacting your clients, there are a few things that you can do to reduce the impact of the change. If you control the clients that are connecting to your application, we recommend updating the trust store to include the ISRG Root X1. If you use certificate pinning, remove or update your pin. In general, we discourage all customers from pinning their certificates, as this usually leads to issues during certificate renewals or CA changes.

If you experience issues with the Let’s Encrypt chain change, and you’re using Advanced Certificate Manager or SSL for SaaS on the Enterprise plan, you can choose to switch your certificate to use Google Trust Services as the certificate authority instead.

For more information, please refer to our developer documentation.

While this change will impact a very small portion of clients, we support the shift that Let’s Encrypt is making as it supports a more secure and agile Internet.

Looking back, there were a number of challenges that slowed down the adoption of new technologies and standards that helped make the Internet faster, more secure, and more reliable.

For starters, before Cloudflare launched Universal SSL, free certificates were not attainable. Instead, domain owners had to pay around $100 to get a TLS certificate. For a small business, this is a big cost and without browsers enforcing TLS, this significantly hindered TLS adoption for years. Insecure algorithms have taken decades to deprecate due to lack of support of new algorithms in browsers or devices. We learned this lesson while deprecating SHA-1.

Supporting new security standards and protocols is vital for us to continue improving the Internet. Over the years, big and sometimes risky changes were made in order for us to move forward. The launch of Let’s Encrypt in 2015 was monumental. Let’s Encrypt allowed every domain to get a TLS certificate for free, which paved the way to a more secure Internet, with now around 98% of traffic using HTTPS.

In 2014, Cloudflare launched elliptic curve digital signature algorithm (ECDSA) support for Cloudflare-issued certificates and made the decision to issue ECDSA-only certificates to free customers. This boosted ECDSA adoption by pressing clients and web operators to make changes to support the new algorithm, which provided the same (if not better) security as RSA while also improving performance. In addition to that, modern browsers and operating systems are now being built in a way that allows them to constantly support new standards, so that they can deprecate old ones.

For us to move forward in supporting new standards and protocols, we need to make the Public Key Infrastructure (PKI) ecosystem more agile. By retiring the cross-signed chain, Let’s Encrypt is pushing devices, browsers, and clients to support adaptable trust stores. This allows clients to support new standards without causing a breaking change. It also lays the groundwork for new certificate authorities to emerge.

Today, one of the main reasons why there’s a limited number of CAs available is that it takes years for them to become widely trusted, that is, without cross-signing with another CA. In 2017, Google launched a new publicly trusted CA, Google Trust Services, that issued free TLS certificates. Even though they launched a few years after Let’s Encrypt, they faced the same challenges with device compatibility and adoption, which caused them to cross-sign with GlobalSign’s CA. We hope that, by the time GlobalSign’s CA comes up for expiration, almost all traffic is coming from a modern client and browser, meaning the change impact should be minimal.

The next 12 months have the potential to reshape the global political landscape with elections occurring in more than 80 nations, in 2024, while new technologies, such as AI, capture our imagination and pose new security challenges.

Against this backdrop, the role of CISOs has never been more important. Grant Bourzikas, Cloudflare’s Chief Security Officer, shared his views on what the biggest challenges currently facing the security industry are in the Security Week opening blog.

Over the past week, we announced a number of new products and features that align with what we believe are the most crucial challenges for CISOs around the globe. We released features that span Cloudflare’s product portfolio, ranging from application security to securing employees and cloud infrastructure. We have also published a few stories on how we take a Customer Zero approach to using Cloudflare services to manage security at Cloudflare.

We hope you find these stories interesting and are excited by the new Cloudflare products. In case you missed any of these announcements, here is a recap of Security Week:

Thanks for joining us this week, and stay tuned for our next Innovation Week in early April, focused on the developer community.