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NIST has updated the NVD program announcement page with additional information regarding recent concerns and the temporary delays in enrichment efforts.

CVE-2022-31021 Detail


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.


CVSS 3.x Severity and Metrics:

Base Score:  5.3 MEDIUM
Vector:  CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Nist CVSS score does not match with CNA score
CNA:  GitHub, Inc.
Base Score:  3.3 LOW
Vector:  CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N

NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: It is possible that the NVD CVSS may not match that of the CNA. The most common reason for this is that publicly available information does not provide sufficient detail or that information simply was not available at the time the CVSS vector string was assigned.

References to Advisories, Solutions, and Tools

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Hyperlink Resource
https://github.com/hyperledger/ursa/security/advisories/GHSA-2q6j-gqc4-4gw3 Vendor Advisory 
https://www.brics.dk/RS/98/29/BRICS-RS-98-29.pdf Exploit  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-829 Inclusion of Functionality from Untrusted Control Sphere Provider acceptance level GitHub, Inc.  

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Change History

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Quick Info

CVE Dictionary Entry:
NVD Published Date:
NVD Last Modified:
GitHub, Inc.