Grav Login OAuth Plugin Authentication Bypass Vulnerability

The Grav Login OAuth plugin (grav-plugin-login-oauth) before version 1.4.3 contains an authentication bypass vulnerability in how OAuth accounts are provisioned.

OAuth accounts are created as ordinary Grav users with a deterministic . username and an unsalted MD5 hash of the provider identifier as the password, without disabling password login.

• Affected versions: before 1.4.3
• Precondition: attacker learns or guesses a provider identifier
• Impact: unauthenticated remote attacker can reproduce these credentials and log in, gaining administrative control of privileged accounts