Tinyauth is an authentication and authorization server. Prior to 5.0.3, the OIDC authorization endpoint allows users with a TOTP-pending session (password verif…

Tinyauth authentication and authorization server contains a vulnerability in versions prior to 5.0.3 where the OIDC authorization endpoint allows users with TOTP-pending sessions to obtain authorization codes. An attacker with knowledge of a user's password but not their TOTP secret can obtain valid OIDC tokens, completely bypassing the second factor authentication. This represents a significant security flaw in multi-factor authentication implementation. The vulnerability has been fixed in version 5.0.3.