Cloudflare Breach Incident Score: Analysis & Impact (CLO1768841812)

In this Rankiteo incident briefing, we review the Cloudflare breach identified under incident ID CLO1768841812.

The analysis begins with a detailed overview of Cloudflare's information like the linkedin page: https://www.linkedin.com/company/cloudflare, the number of followers: 1125000, the industry type: Computer and Network Security and the number of employees: 6599 employees

After the initial compromise, the video explains how Rankiteo's incident engine converts technical details into a normalized incident score. The incident score before the incident was 635 and after the incident was 632 with a difference of -3 which is could be a good indicator of the severity and impact of the incident.

In the next step of the video, we will analyze in more details the incident and the impact it had on Cloudflare and their customers.

Cloudflare recently reported "Critical Zero-Day in Cloudflare WAF Exposed Origin Servers to Bypass Attacks", a noteworthy cybersecurity incident.

Security researchers from FearsOff uncovered a zero-day vulnerability in Cloudflare’s Web Application Firewall (WAF) that allowed attackers to bypass security controls and directly access protected origin servers.

The disruption is felt across the environment, affecting Origin servers protected by Cloudflare WAF, and exposing Database credentials, API tokens, cloud keys, server-side rendering data, local file inclusion vulnerabilities.

In response, moved swiftly to contain the threat with measures like Permanent fix deployed to ensure WAF rules apply uniformly to all paths, and began remediation that includes Cloudflare validated and triaged the issue, deploying a fix on October 27, 2025, and stakeholders are being briefed through Public disclosure via HackerOne and company statement.

The case underscores how Resolved, teams are taking away lessons such as Improper handling of ACME HTTP-01 challenge paths can create unintended bypass vectors in WAF systems. Regular audits of edge network logic are necessary to prevent similar vulnerabilities, and recommending next steps like Cloudflare customers were advised that no action was required post-fix. Organizations should verify WAF rule consistency across all paths, including ACME challenge directories, with advisories going out to stakeholders covering Cloudflare confirmed no evidence of malicious exploitation and stated no customer action was required.

Finally, we try to match the incident with the MITRE ATT&CK framework to see if there is any correlation between the incident and the MITRE ATT&CK framework.

The MITRE ATT&CK framework is a knowledge base of techniques and sub-techniques that are used to describe the tactics and procedures of cyber adversaries. It is a powerful tool for understanding the threat landscape and for developing effective defense strategies.

Rankiteo's analysis has identified several MITRE ATT&CK tactics and techniques associated with this incident, each with varying levels of confidence based on available evidence. Under the Initial Access tactic, the analysis identified Exploit Public-Facing Application (T1190) with high confidence (90%), with evidence including zero-day vulnerability in Cloudflare’s Web Application Firewall (WAF), and allowed attackers to bypass security controls. Under the Defense Evasion tactic, the analysis identified Impair Defenses: Disable or Modify Tools (T1562.001) with high confidence (95%), with evidence including aCME HTTP-01 challenge paths...evade WAF rules entirely, and wAF was completely bypassed if token didn’t match and Disabling Security Tools (T1089) with moderate to high confidence (80%), with evidence including bypass of WAF rules for ACME path traffic, and custom WAF rules bypassed for header-based blocking. Under the Credential Access tactic, the analysis identified Unsecured Credentials: Credentials In Files (T1552.001) with moderate to high confidence (80%), supported by evidence indicating database credentials, API tokens, and cloud keys exposed via actuator endpoints. Under the Collection tactic, the analysis identified Data from Local System (T1005) with moderate to high confidence (85%), supported by evidence indicating server-side rendering data leaked through unintended public responses and Data from Cloud Storage (T1530) with moderate to high confidence (70%), supported by evidence indicating origin-generated responses included sensitive data. Under the Exfiltration tactic, the analysis identified Exfiltration Over C2 Channel (T1041) with moderate to high confidence (70%), with evidence including potential unauthorized access to origin servers, and data breach risks via path traversal. These correlations help security teams understand the attack chain and develop appropriate defensive measures based on the observed tactics and techniques.