dbcve.org
UrsaApplication · Hyperledger

CVE-2024-21670

HIGH · 8.1 CVSS v3.1 Published 2024-01-16
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
90/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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 A verifier may verify a credential from a holder as being "not revoked" when in fact, the holder's credential has been revoked.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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

The vulnerability exists in Ursa's CL-Signatures implementation's revocation schema. A flaw allows a malicious holder of a revoked AnonCreds credential to generate a valid Non-Revocation Proof, causing verifiers to incorrectly accept the revoked credential as 'not revoked' and thereby bypassing the revocation check entirely.

MitigationSince Ursa is end-of-life with no fix forthcoming, organizations must migrate to alternative cryptographic libraries supporting AnonCreds and implement compensating controls such as additional credential status verification through issuer-provided revocation registries.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
UrsaApplication
Affected:= 0.1.0

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Hyperledger Ursa installation
    Search for Hyperledger Ursa library files or dependencies in your project (e.g., cargo crate 'ursa' for Rust, or Python package 'ursa' if applicable). Check your dependency manifest files (Cargo.toml, package.json, requirements.txt, etc.) for the 'ursa' package.
    Affected if Hyperledger Ursa is present as a dependency or installed library
  2. Verify Ursa version is 0.1.0
    Check the installed or pinned version of the Ursa library in your dependency lock files or installed packages. Compare against the exact version = 0.1.0.
    Affected if The installed version of Hyperledger Ursa is exactly 0.1.0
  3. Confirm CL-Signatures revocation is in use
    Inspect your code or configuration to determine if the CL-Signatures implementation within Ursa is being used, particularly for credential issuance or verification workflows involving revocation.
    Affected if Your application uses CL-Signatures from Ursa for credential operations with revocation support
  4. Check for AnonCreds credential verification
    Review your credential verification logic to identify if AnonCreds-style credentials are being validated, specifically looking for non-revocation proof generation or verification calls.
    Affected if Your system processes AnonCreds credentials and performs non-revocation proofs

You are affected if Hyperledger Ursa version 0.1.0 is installed and your system uses CL-Signatures for AnonCreds credential verification with revocation proofs.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Since Ursa is end-of-life with no fix forthcoming, organizations must migrate to alternative cryptographic libraries supporting AnonCreds and implement compensating controls such as additional credential status verification through issuer-provided revocation registries.

Recommended fix High confidence
  1. This vulnerability has no remediation path. Ursa has been declared end-of-life by the maintainers.
  2. Migrate away from Ursa to an actively maintained cryptographic library that supports AnonCreds verifiable credentials.
  3. If AnonCreds compatibility is required, evaluate alternative implementations such as Hyperledger AnonCreds (Indy) or other actively supported libraries.
  4. Review any existing deployments using Ursa 0.1.0 and assess the impact of credential fraud due to this revocation bypass vulnerability.
Caveat Ursa is end-of-life with no successor version; a full migration to an alternative library is required.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Ursa Scoped from the published advisory
  • Consultation16.0 h
  • Implementation40.0 h
  • Testing24.0 h
  • Review / QA12.0 h
92.0 hours of engineering $16,160
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2024-21670 in production — separate from our analysis above.

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