This tweet reports a Web Application Firewall (WAF) bypass related to Cross-Site Scripting (XSS) that is cookie based. It states that the combination '41+33' allows bypassing an 'Access Denied | WAF Block' response. Beyond bypassing the WAF, the tweet also mentions privilege escalation resulting in admin access, indicating a severe security impact. However, the tweet does not specify which WAF vendor is affected or provide detailed technical data about how this bypass works. The bypass appears to exploit a weakness in the WAF's detection of malicious cookie values related to XSS payloads. This means an attacker can potentially bypass protections to execute XSS attacks and then use that vector to escalate privileges to an administrator level. Without more details, it is advisable for security teams to review WAF rules regarding cookie inspection and XSS protections, check for anomalous cookie values, and investigate privilege escalation paths stemming from XSS vulnerabilities. Detailed analysis and patching are necessary to close this security gap.
For more insights, check out the original tweet here: https://twitter.com/r0ckinthehacker/status/1972321312556380553