phpMyFAQ - Unauthenticated Two-Factor Authentication Brute-Force via /admin/check Endpoint

phpMyFAQ before 4.1.2 contains an improper restriction of excessive authentication attempts vulnerability in the /admin/check endpoint, which accepts arbitrary user-id parameters without session binding or rate limiting. Unauthenticated attackers can brute-force any user's six-digit TOTP code by submitting POST requests with sequential token values, bypassing two-factor authentication to gain full administrative access.