Description
pac4j-oidc before 6.5.6 accepts OIDC callbacks carrying only an access token without authorization code or ID token validation. Attackers can substitute access tokens minted for other clients to create authenticated sessions without proper issuer, audience, nonce, or subject verification.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| pac4j | pac4j | < 6.5.6 | 6.5.6 |
References
- Patch Commit patch
- pac4j Security Advisory for pac4j-core, pac4j-oidc and pac4j-saml vendor-advisory
- https://github.com/pac4j/pac4j/blob/pac4j-parent-6.5.5/pac4j-oidc/src/main/java/org/pac4j/oidc/credentials/extractor/OidcCredentialsExtractor.java technical-description
- https://github.com/pac4j/pac4j product
- VulnCheck Advisory: pac4j-oidc before 6.5.6 Authentication Bypass via Access Token Substitution third-party-advisory