CVE-2022-31021: hyperledger ursa

Vulnerability summary

CVE-2022-31021 is a medium (CVSS 5.3) vulnerability in hyperledger ursa. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.6% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-01-2024
   PublishedVulnerability first disclosed.
2. 02-06-2025
   Last modifiedVulnerability information updated.

Description

Ursa is a cryptographic library for use with blockchains. A weakness in the Hyperledger AnonCreds specification that is not mitigated in the Ursa and AnonCreds implementations is that the Issuer does not publish a key correctness proof demonstrating that a generated private key is sufficient to meet the unlinkability guarantees of AnonCreds. The Ursa and AnonCreds CL-Signatures implementations always generate a sufficient private key. A malicious issuer could in theory create a custom CL Signature implementation (derived from the Ursa or AnonCreds CL-Signatures implementations) that uses weakened private keys such that presentations from holders could be shared by verifiers to the issuer who could determine the holder to which the credential was issued. This vulnerability could impact holders of AnonCreds credentials implemented using the CL-signature scheme in the Ursa and AnonCreds implementations of CL Signatures. The ursa project has has moved to end-of-life status and no fix is expected.

• CWE-829Inclusion of Functionality from Untrusted Control SphereThe product imports, requires, or includes executable functionality (such as a library) from a source that is outside of the intended control sphere.