{"id":"CVE-2024-21670","aliases":["GHSA-r78f-4q2q-hvv4"],"url":"https://o3.security/vulnerability/CVE-2024-21670","summary":"CL-Signatures Revocation Scheme in Ursa has flaws that allow a holder to demonstrate non-revocation of a revoked credential","details":"Ursa is a cryptographic library for use with blockchains. The revocation schema that is part of the Ursa CL-Signatures implementations has a flaw that could impact the privacy guarantees defined by the AnonCreds verifiable credential model, allowing a malicious holder of a revoked credential to generate a valid Non-Revocation Proof for that credential as part of an AnonCreds presentation. A verifier may verify a credential from a holder as being \"not revoked\" when in fact, the holder's credential has been revoked. Ursa has moved to end-of-life status and no fix is expected.","published":"2024-01-16T21:44:05.572Z","modified":"2026-08-12T03:51:35.311118988Z","cvss":{"score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:P/AC:H/PR:H/UI:R/S:C/C:H/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"crates.io","name":"ursa","fixedVersion":null},{"ecosystem":"crates.io","name":"anoncreds-clsignatures","fixedVersion":null}],"fix":null,"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/21xxx/CVE-2024-21670.json"},{"type":"ADVISORY","url":"https://github.com/hyperledger-archives/ursa/security/advisories/GHSA-r78f-4q2q-hvv4"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-21670"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:35.311118988Z"}}