CVE-2026-33667: OpenProject: 2FA OTP Verification Missing Rate Limiting

OpenProject is an open-source project management application. In versions prior to 17.3.0, 2FA OTP verification in the confirmotp action of the twofactorauthentication module has no rate limiting, lockout mechanism, or failed-attempt tracking. The existing bruteforceblockafterfailedlogins setting only counts password login failures and does not apply to the 2FA verification stage, and neither the faillogin nor stagefailure methods increment any counter, lock the account, or add any delay. With the default TOTP drift window of ±60 seconds allowing approximately 5 valid codes at any time, an attacker who knows a user's password can brute-force the 6-digit TOTP code at roughly 5-10 attempts per second with an expected completion time of approximately 11 hours. The same vulnerability applies to backup code verification. This effectively allows complete 2FA bypass for any account where the password is known. This issue has been fixed in version 17.3.0.