Description
Ursa is a cryptographic library for use with blockchains. The revocation scheme 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. Notably, a malicious verifier may be able to generate a unique identifier for a holder providing a verifiable presentation that includes a Non-Revocation proof. The impact of the flaw is that a malicious verifier may be able to determine a unique identifier for a holder presenting a Non-Revocation proof. Ursa has moved to end-of-life status and no fix is expected.
Scores
CVSS v3
6.5
EPSS
0.0018
EPSS Percentile
39.2%
Attack Vector
NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
CISA SSVC
Vulnrichment
Exploitation
none
Automatable
no
Technical Impact
partial
Details
CWE
CWE-327
Status
published
Products (3)
crates.io/anoncreds-clsignatures
0 - 0.1.0crates.io
crates.io/ursa
0crates.io
hyperledger/ursa
0.1.0
Published
Jan 16, 2024
Tracked Since
Feb 18, 2026