JOSE is a Javascript Object Signing and Encryption (JOSE) library. Prior to version 0.3.5+1, a vulnerability in jose could allow an unauthenticated, remote attacker to forge valid JWS/JWT tokens by using a key embedded in the JOSE header (jwk). The vulnerability exists because key selection could treat header-provided jwk as a verification candidate even when that key was not present in the trusted key store. Since JOSE headers are untrusted input, an attacker could exploit this by creating a token payload, embedding an attacker-controlled public key in the header, and signing with the matching private key. Applications using affected versions for token verification are impacted. This issue has been patched in version 0.3.5+1. A workaround for this issue involves rejecting tokens where header jwk is present unless that jwk matches a key already present in the application's trusted key store.

Affected: Pub: jose

### Impact

A vulnerability in `jose` versions up to and including `0.3.5` could allow an unauthenticated, remote attacker to forge valid JWS/JWT tokens by using a key embedded in the JOSE header (`jwk`).

The vulnerability exists because key selection could treat header-provided `jwk` as a verification candidate even when that key was not present in the trusted key store. Since JOSE headers are untrusted input, an attacker could exploit this by creating a token payload, embedding an attacker-controlled public key in the header, and signing with the matching private key.

Applications using affected versions for token verification are impacted.

### Patches

Upgrade to `0.3.5+1` or later.

### Workarounds

Reject tokens where header `jwk` is present unless that `jwk` matches a key already present in the application's trusted key store.

### Resources

Fix commit: [fix: improved key resolution in JsonWebKeyStore](https://github.com/appsup-dart/jose/commit/b07799aac1f56a9a21483feac026272aab30cc5d)