This tweet mentions a potential method to bypass a Web Application Firewall (WAF) specifically for stored Cross-Site Scripting (XSS) vulnerabilities. However, it does not provide a specific payload or detailed technical information. Stored XSS occurs when malicious script is permanently stored on a target server and displayed to other users. Bypassing the WAF in this context means evading the firewall's filters designed to detect and block such malicious scripts. Since the vendor of the WAF is not specified and no payload is included, detailed analysis is limited. For anyone interested in this topic, it's important to understand that different WAF products have varying rules and detection capabilities. Techniques to bypass them often involve obfuscation or unusual encoding of the XSS payload to evade pattern matching rules. This tweet suggests there could be useful techniques, but without more information, practitioners should continue researching or testing with their specific WAF environment in mind.
For more details, check out the original tweet here: https://twitter.com/LooseSecurity/status/1937256943891960054