Headline
CVE-2023-23928: Jws ignores signature checks
reason-jose is a JOSE implementation in ReasonML and OCaml.Jose.Jws.validate does not check HS256 signatures. This allows tampering of JWS header and payload data if the service does not perform additional checks. Such tampering could expose applications using reason-jose to authorization bypass. Applications relying on JWS claims assertion to enforce security boundaries may be vulnerable to privilege escalation. This issue has been patched in version 0.8.2.
Impact
Jose.Jws.validate does not check HS256 signatures. This allows tampering of JWS header and payload data if the service does not perform additional checks.
Such tampering could expose applications using reason-jose to authorisation bypass.
Applications relying on JWS claims assertion to enforce security boundaries may be vulnerable to privilege escalation.
Patches
0.8.2
Workarounds
If you can avoid using symmetric keys and instead use asymmetric keys that should be working as intended already.