OpenID Connect nonce generated but never validated — ID token replay attack

Summary

The roadiz/openid package generates an OIDC nonce in OAuth2LinkGenerator::generate() and includes it in the authorization request sent to the identity provider, but never stores it and never validates it on the callback. The OpenIdJwtConfigurationFactory validation chain does not include a nonce constraint, and OpenIdAuthenticator::authenticate() never checks the nonce claim in the returned ID token against a stored value.

Details

In src/OAuth2LinkGenerator.php, a nonce is created and sent to the IdP:

'nonce' => $this->tokenGenerator->generateToken(),

However, this value is neither stored in session, cache, nor any other persistent store.

In src/OpenIdJwtConfigurationFactory.php, the JWT validation constraints are:

• LooseValidAt (expiry)
• PermittedFor (audience)
• IssuedBy (issuer)
• HostedDomain (optional)
• UserInfoEndpoint (optional)

No nonce constraint is present.

In src/Authentication/OpenIdAuthenticator.php, the authenticate() method validates the state CSRF token correctly (fixed in v2.7.10), but never retrieves a stored nonce or compares it against the nonce claim in the ID token.

PoC

1. Obtain a valid ID token from a legitimate OIDC flow for a target user (e.g. via network interception, browser history leak, or referrer header exposure on a non-HTTPS redirect).
2. Replay the ID token: Since the nonce in the token is never cross-checked against a client-stored value, the token passes all validation constraints as long as it has not expired.
3. Result: An attacker can authenticate as the victim within the ID token's validity window.

Additionally, in an authorization code flow with multiple concurrent sessions, a malicious IdP or a compromised token endpoint could inject a token with a mismatched nonce, and the application would accept it silently.

Impact

• ID token replay attacks: Valid but intercepted tokens can be reused for authentication within their validity period.
• Token injection attacks: A malicious or compromised identity provider can inject tokens across sessions without detection.
• Affects any Roadiz application using the roadiz/openid package with OpenID Connect SSO.

The OIDC Core 1.0 specification (Section 3.1.3.7) explicitly requires clients to verify the nonce claim if it was present in the authorization request.