Loosebazooka

Name of the Vulnerable Software and Affected Versions: sigstore-java versions prior to 1.2.0 Description: The issue is related to insufficient verification for a situation where a bundle provides an invalid signature for a checkpoint. This affects clients using any variation of `KeylessVerifier.verify()`. The impact is low for clients that are not monitors or witnesses, as other mechanisms like signed entry timestamps mitigate this issue. A valid signed entry timestamp is still required for verification to pass. Recommendations: For versions prior to 1.2.0, update to version 1.2.0 to fix the issue. As a temporary workaround, verifiers may choose to verify the checkpoint manually after running `KeylessVerifier.verify()` by using the provided Java code to manually verify the checkpoint signature.

**Name of the Vulnerable Software and Affected Versions** sigstore-java versions prior to v1.1.0 **Description** The issue is related to insufficient verification in sigstore-java for a situation where a validly-signed but "mismatched" bundle is presented as proof of inclusion into a transparency log. This bug impacts clients using any variation of KeylessVerifier.verify(). The verifier may accept a bundle with an unrelated log entry, cryptographically verifying everything but fails to ensure the log entry applies to the artifact in question. This allows the creation of a bundle without fulcio certificate and private key combined with an unrelated but time-correct log entry to fake logging of a signing event. A malicious actor using a compromised identity may want to do this to prevent discovery via rekor's log monitors. **Recommendations** For versions prior to v1.1.0, update to v1.1.0 or later to resolve the issue. As a temporary workaround, verifiers can recreate the log entry and compare it to the provided log entry, or contact the log and discover if the artifact signing event has indeed been added to the log.