This tweet shows a simple example of bypassing a WAF (Web Application Firewall). Normally, when accessing the '/register' URL, the WAF blocks the request and returns a 403 Forbidden status. However, by adding a query parameter to the URL, making it '/register?cb=titifelbro47', the request succeeds with a 200 OK status. This indicates that the WAF is likely filtering or blocking specific URLs but does not properly handle URLs with query parameters. By adding seemingly random parameters like 'cb=titifelbro47', attackers might confuse the WAF and successfully bypass its protections. This bypass technique is universal and could potentially work against any WAF that does not strictly validate URLs with parameters. Hackers or bug bounty hunters can use this trick to access restricted pages or resources that are otherwise blocked by the WAF, potentially allowing further exploitation of vulnerabilities on the target server. It is recommended for security teams to configure their WAFs to apply the same strict filtering regardless of URL parameters to avoid this bypass.
For more insights, check out the original tweet here: https://twitter.com/TitifelBro47/status/1970043503725166879