PLANKA 2.2.0 through 2.2.1 fails to limit incorrect TOTP codes submitted to POST /api/access-tokens/verify-totp, allowing attackers to brute force two-factor authentication codes. Attackers who know a users password can reuse the ten-minute pending token to guess six-digit codes until one succeeds, obtaining a full access token.
The product does not implement sufficient measures to prevent multiple failed authentication attempts within a short time frame.
Common protection mechanisms include:
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid [REF-1482].
Consider using libraries with authentication capabilities such as OpenSSL or the ESAPI Authenticator. [REF-45]