CVE-2023-44273
📋 TL;DR
CVE-2023-44273 is a signature malleability vulnerability in Consensys gnark-crypto cryptographic library that allows attackers to create multiple valid signatures for the same message by manipulating signature data during deserialization. This affects applications using gnark-crypto for EdDSA or ECDSA signature verification, potentially enabling signature forgery or replay attacks. The vulnerability impacts any system using vulnerable versions of this library for cryptographic operations.
💻 Affected Systems
- Consensys gnark-crypto
📦 What is this software?
Gnark Crypto by Consensys
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of cryptographic integrity allowing signature forgery, authentication bypass, transaction manipulation in blockchain applications, and potential financial loss or unauthorized access.
Likely Case
Signature replay attacks, transaction manipulation in systems using vulnerable signatures for verification, and potential authentication bypass in affected applications.
If Mitigated
Limited impact with proper signature validation controls, but still presents cryptographic integrity risks that could be exploited in targeted attacks.
🎯 Exploit Status
Exploitation requires understanding of cryptographic signature manipulation and access to systems using vulnerable signature verification. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.12.0 and later
Vendor Advisory: https://github.com/Consensys/gnark-crypto/releases
Restart Required: Yes
Instructions:
1. Update gnark-crypto dependency to version 0.12.0 or later. 2. Update go.mod to require github.com/Consensys/gnark-crypto v0.12.0 or higher. 3. Rebuild and redeploy affected applications. 4. Restart services using the updated library.
🔧 Temporary Workarounds
Implement custom signature validation
allAdd additional validation to ensure signatures are in the proper interval before accepting them
// Add validation logic in signature verification code to check signature bounds
🧯 If You Can't Patch
- Implement additional signature validation layers to check for signature malleability
- Monitor for unusual signature patterns and implement rate limiting on signature verification operations
🔍 How to Verify
Check if Vulnerable:
Check go.mod or dependency files for gnark-crypto version. If version is <=0.11.2, the system is vulnerable.Check Version:
go list -m github.com/Consensys/gnark-cryptoVerify Fix Applied:
Verify gnark-crypto version is >=0.12.0 in dependencies and rebuild applications with the updated library.📡 Detection & Monitoring
Log Indicators:
- Multiple valid signatures for same message
- Signature verification failures with unusual parameters
- Unexpected signature validation successes
Network Indicators:
- Repeated transactions with modified signatures
- Unusual signature patterns in cryptographic operations
SIEM Query:
Search for signature verification events with identical message content but different signature values