phpMyFAQ WebAuthn Authentication Bypass Flaw

phpMyFAQ 4.0.0 before 4.1.9 contains an authentication bypass vulnerability in its WebAuthn registration endpoints. These endpoints attach credentials to any account without authentication or challenge validation.

Attackers can:

• Stage a victim username.
• Submit a forged fmt=none attestation to register a passkey.

This allows them to log in bypassing passwords and TOTP for account takeover.