CVE-2024-22192 Overview
CVE-2024-22192 affects Hyperledger Ursa, a cryptographic library used in blockchain and verifiable credential ecosystems. The flaw resides in the revocation scheme of the CL-Signatures implementation used by the AnonCreds verifiable credential model. A malicious verifier can derive a unique identifier for a holder who presents a Non-Revocation proof, breaking the anonymity guarantees the protocol is designed to provide. Ursa has reached end-of-life status, and the maintainers do not plan to issue a fix. Downstream consumers of the library must migrate to actively maintained AnonCreds implementations to remove exposure.
Critical Impact
A malicious verifier can correlate presentations from the same holder, defeating the unlinkability promise of AnonCreds Non-Revocation proofs [CWE-327].
Affected Products
- Hyperledger Ursa 0.1.0 (Rust implementation)
- AnonCreds deployments relying on Ursa CL-Signatures for Non-Revocation proofs
- Downstream verifiable credential frameworks that embed the Ursa revocation scheme
Discovery Timeline
- 2024-01-16 - CVE-2024-22192 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2024-22192
Vulnerability Analysis
Hyperledger Ursa implements Camenisch-Lysyanskaya (CL) signatures, which underpin AnonCreds verifiable credentials. AnonCreds allows a holder to prove attributes and non-revocation status without revealing a persistent identifier. The flaw in the revocation scheme causes the Non-Revocation proof to leak a value that a verifier can use as a stable, holder-specific identifier. Two independent verifications from the same holder become linkable across sessions and across verifiers who collude. This undermines the privacy model that AnonCreds is intended to enforce.
The issue is categorized under [CWE-327] as the use of a broken or risky cryptographic algorithm, specifically an incorrectly constructed revocation proof. Because Ursa is end-of-life, no upstream cryptographic patch will be issued. Consumers must move to maintained AnonCreds cryptographic backends that implement the corrected revocation scheme.
Root Cause
The Non-Revocation proof construction in the Ursa CL-Signatures module produces values that are deterministic with respect to the holder's credential secret. A verifier examining the proof transcript can therefore recognize repeat presentations by the same holder, even across independent presentation sessions.
Attack Vector
Exploitation requires the holder to voluntarily present a verifiable credential with a Non-Revocation proof to a verifier controlled or observed by the attacker. The attack is passive from the network perspective; the malicious verifier simply records proof material from presentations. Correlating presentations across services yields a persistent pseudonymous identifier for the holder. No credential theft or key compromise is required.
The vulnerability mechanism is described in the Hyperledger Ursa Security Advisory GHSA-6698-mhxx-r84g. No public proof-of-concept exploit code has been published.
Detection Methods for CVE-2024-22192
Indicators of Compromise
- Presence of the hyperledger:ursa crate at version 0.1.0 in Rust dependency manifests (Cargo.toml, Cargo.lock)
- Runtime linkage to Ursa CL-Signatures modules within AnonCreds issuer, holder, or verifier services
- Verifier services logging or persisting raw Non-Revocation proof components beyond the verification decision
Detection Strategies
- Perform software composition analysis across code repositories and container images to enumerate all uses of hyperledger:ursa
- Inspect verifiable credential stacks (Aries, Indy, AnonCreds RS) to confirm which cryptographic backend handles Non-Revocation proofs
- Review verifier application logs for retention of proof primitives that could be used for cross-session correlation
Monitoring Recommendations
- Track outbound presentations to unknown verifiers from holder wallets that still rely on Ursa
- Alert on new deployments or container builds that reintroduce the archived Ursa crate
- Monitor upstream advisories from Hyperledger AnonCreds and Aries projects for continued migration guidance
How to Mitigate CVE-2024-22192
Immediate Actions Required
- Inventory all systems that depend on hyperledger:ursa, including transitive dependencies
- Migrate AnonCreds workloads to the maintained anoncreds-rs implementation, which supersedes Ursa
- Restrict Non-Revocation proof presentation from holder wallets that cannot yet be migrated
- Assess prior verifier interactions to determine whether holder correlation is already feasible
Patch Information
No patch will be released. Hyperledger Ursa is archived and has reached end-of-life status per the GHSA-6698-mhxx-r84g advisory. Remediation requires replacing Ursa with a supported cryptographic library that implements a corrected revocation scheme.
Workarounds
- Disable Non-Revocation proofs in verifier policy where revocation status is not strictly required
- Rotate holder credentials after migration so that new proofs cannot be linked to pre-migration presentations
- Constrain credential presentation to trusted verifiers until migration completes
- Adopt AnonCreds specifications and libraries that have moved off Ursa CL-Signatures
# Identify Ursa usage in Rust projects
grep -R "ursa" Cargo.toml Cargo.lock
cargo tree -i ursa
# Remove the archived dependency and migrate to anoncreds-rs
cargo remove ursa
cargo add anoncreds
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.