FlaskBB is a Forum Software written in Python using the micro framework Flask. Prior to version 2.2.1, a Server-Side Request Forgery (SSRF) vulnerability in get_image_info() allows any authenticated user to force the server to send HTTP requests to arbitrary internal endpoints, including cloud metadata services. This is a blind SSRF with confirmed internal port scanning and internal API triggering capabilities. Version 2.2.1 patches the issue.

FlaskBB through 2.2.0, fixed in commit acc88cf, contains an authorization bypass vulnerability that allows authenticated moderators to perform unauthorized actions on topics in forums they do not control by submitting crafted topic ID lists. Attackers can include a low-ID topic from a permitted forum as an anchor in a batch request, causing the permission check applied only to the first result to pass, and then execute lock, unlock, delete, or hide actions against topics in unmoderated forums.

FlaskBB through 2.2.0, fixed in commit a5da9a5, contains a logic flaw vulnerability that allows authenticated administrators to delete all built-in authorization groups by exploiting a type mismatch in the bulk delete protection check. The bulk AJAX endpoint in the management views compares received JSON integer group IDs against string literals, causing the protection check to always pass, which allows deletion of all six built-in groups and destroys the forum's permission model, potentially rendering the site unusable.