This tweet mentions a Stored Cross-Site Scripting (XSS) vulnerability that can bypass the Cloudflare Web Application Firewall (WAF). Stored XSS is a type of security vulnerability where malicious scripts are injected into a web application and stored on the server, which then get executed in the browsers of users who visit the affected pages. Cloudflare WAF is a popular security service designed to detect and block attacks like XSS. However, the tweet implies that there is a way to bypass Cloudflare's WAF protections for Stored XSS attacks. This means an attacker may still successfully inject and execute malicious scripts even with Cloudflare's defenses in place. Unfortunately, the tweet does not provide the specific payload or technical details on how the bypass is accomplished. More information or a detailed write-up would be needed to understand the method used for this WAF bypass.
Original tweet: https://twitter.com/bbwriteups/status/1964600933230469163