Description
OpenID Connect Core through 1.0 errata set 2 allows audience injection in certain situations. When the private_key_jwt authentication mechanism is used, a malicious Authorization Server could trick a Client into writing attacker-controlled values into the audience, including token endpoints or issuer identifiers of other Authorization Servers. The malicious Authorization Server could then use these private key JWTs to impersonate the Client.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
OpenID OpenID Connect
Default version status: unknown
0 to ≤ 1.0 errata set 2affected
References
- https://openid.net/wp-content/uploads/2025/01/OIDF-Responsible-Disclosure-Notice-on-Security-Vulnerability-for-private_key_jwt.pdf ↗
- https://openid.net/notice-of-a-security-vulnerability/ ↗
- https://talks.secworkshop.events/osw2025/talk/R8D9BS/ ↗
- https://github.com/OWASP/ASVS/issues/2678 ↗
- https://eprint.iacr.org/2025/629 ↗