WWBN/AVideo has CAPTCHA Bypass via Attacker-Controlled Length Parameter and Missing Token Invalidation on Failure
WWBN AVideo is an open source video platform. In versions 29.0 and prior, `objects/getCaptcha.php` accepts the CAPTCHA length (`ql`) directly from the query string with no clamping or sanitization, letting any unauthenticated client force the server to generate a 1-character CAPTCHA word. Combined with a case-insensitive `strcasecmp` comparison over a ~33-character alphabet and the fact that failed validations do NOT consume the stored session token, an attacker can trivially brute-force the CAPTCHA on any endpoint that relies on `Captcha::validation()` (user registration, password recovery, contact form, etc.) in at most ~33 requests per session. Commit bf1c76989e6a9054be4f0eb009d68f0f2464b453 contains a fix.
AV:NAttack VectorAC:LAttack ComplexityPR:NPrivileges RequiredUI:NUser InteractionS:UScopeC:NConfidentialityI:LIntegrityA:NAvailabilityGet the full picture for CVE-2026-40935 and every CVE in our database. Create a free account — no credit card required.
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