CVE-2024-43366
📋 TL;DR
This vulnerability in zkvyper (a Vyper compiler for zkSync Era) allows infinite loops in compiled smart contracts due to improper loop exit condition handling in LLL IR. It affects developers using zkvyper versions 1.3.12 through 1.5.2 to compile contracts, potentially leading to loss of funds or unexpected contract behavior.
💻 Affected Systems
- zkvyper (Vyper compiler for zkSync Era)
📦 What is this software?
Zkvyper by Matter Labs
⚠️ Risk & Real-World Impact
Worst Case
Complete loss of funds in affected smart contracts through infinite loops that prevent proper execution or allow malicious exploitation of contract logic.
Likely Case
Contract deployment failures or unexpected gas consumption due to infinite loops during execution, potentially causing financial losses for contract users.
If Mitigated
No impact if contracts are compiled with patched version or if contracts don't use affected loop patterns.
🎯 Exploit Status
Exploitation requires creating or modifying contracts to trigger the vulnerable loop patterns. No known in-the-wild exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.3
Vendor Advisory: https://github.com/matter-labs/era-compiler-vyper/security/advisories/GHSA-8j77-7rrv-6pxx
Restart Required: No
Instructions:
1. Update zkvyper to version 1.5.3 or later using package manager. 2. Recompile all affected contracts with the updated compiler. 3. Redeploy recompiled contracts to replace vulnerable deployments.
🔧 Temporary Workarounds
Avoid vulnerable loop patterns
allManually review and avoid loop patterns that could trigger the infinite loop condition during contract development.
🧯 If You Can't Patch
- Audit all contracts compiled with vulnerable versions for infinite loop patterns
- Implement circuit breakers or emergency stop mechanisms in deployed contracts
🔍 How to Verify
Check if Vulnerable:
Check zkvyper version with 'zkvyper --version' and verify if between 1.3.12 and 1.5.2Check Version:
zkvyper --versionVerify Fix Applied:
Verify zkvyper version is 1.5.3 or higher and recompile contracts📡 Detection & Monitoring
Log Indicators:
- Excessive gas consumption in contract execution
- Contract deployment failures with loop-related errors
Network Indicators:
- Unusually high gas fees for simple contract operations
- Failed contract transactions with out-of-gas errors
SIEM Query:
Not applicable - this is a development/compiler issue