Executive brief
### Summary The OIDC authentication provider unconditionally sets `SkipClientIDCheck: true` in the `go-oidc` verifier configuration, disabling the standard audience (`aud`) claim validation at the library level. This allows tokens issued for unrelated services by the same OIDC issuer to be accepted by Oxia.
### Impact In deployments using OIDC authentication, an attacker possessing a valid JWT token issued by the same identity provider but intended for a different service (different `client_id`/`aud`) can authenticate to Oxia. This bypasses the intended audience isolation of OAuth2/OIDC.
All versions using OIDC authentication are affected.
### Details In `oxiad/common/rpc/auth/oidc.go`, both `createStaticKeyVerifier()` and `createRemoteVerifier()` set `SkipClientIDCheck: true`. While a custom audience check exists in `Authenticate()`, the library-level check — which validates the `aud` claim against the expected `client_id` — is completely bypassed.
### Patches Fixed by removing `SkipClientIDCheck: true` and setting the `ClientID` field from the configured `AllowedAudiences`.
### Workarounds Ensure network-level isolation so that only trusted services can reach the Oxia gRPC endpoints.
Affected products
- Go github.com/oxia-db/oxia