GHSA-hp74-gm6m-2qm5: Pocket ID has a reauthentication bypass via one-time access token login — passkey step-up requirement defeated by JWT freshness check that accepts any login method

A weaker authentication method (OTA token or signup token) is accepted as passkey step-up proof, yielding unauthorized renewable 30-day OIDC refresh tokens for clients explicitly configured with RequiresReauthentication: true. The POST /api/webauthn/reauthenticate endpoint’s access-token fallback checks only JWT freshness (IssuedAt within 60 seconds), not the authentication method used. The session cookie gate is also non-validating – any arbitrary cookie value (e.g. session=deadbeef) is accepted, collapsing the reauth boundary to token recency alone.

The bypass needs to succeed only once. The resulting OIDC grant includes a 30-day refresh token that can be rotated indefinitely, providing persistent victim-impersonation access to the protected downstream service. The attacker obtains access_token (1-hour TTL), id_token (victim’s name, email, profile), and refresh_token (30-day TTL, renewable) for a client that was explicitly configured to require passkey step-up authentication. The attacker can perform victim-scoped actions at the downstream relying party indefinitely.