CVE-2023-46247 – This vulnerability in Vyper smart contract lang... (How to Fix)

Q: What is the severity of CVE-2023-46247?

CVE-2023-46247 has a CVSS score of 7.5 (HIGH). This vulnerability in Vyper smart contract language causes incorrect memory allocation for large arrays, potentially leading to memory corruption. It affects Ethereum smart contracts written in Vyper versions before 0.3.8 that use large arrays. The issue can cause either buffer overflows or underflows depending on array size.

📋 TL;DR

This vulnerability in Vyper smart contract language causes incorrect memory allocation for large arrays, potentially leading to memory corruption. It affects Ethereum smart contracts written in Vyper versions before 0.3.8 that use large arrays. The issue can cause either buffer overflows or underflows depending on array size.

💻 Affected Systems

Products:

Vyper smart contract language

Versions: All versions prior to 0.3.8

Operating Systems: All

Default Config Vulnerable: ⚠️ Yes

Notes: Only affects contracts with large arrays (>2^46 bytes). Most typical smart contracts are not affected.

📦 What is this software?

Vyper by Vyperlang

View all CVEs affecting Vyper →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Smart contract memory corruption leading to arbitrary code execution, fund theft, or contract destruction on the Ethereum blockchain.

🟠

Likely Case

Smart contract malfunction causing incorrect calculations, failed transactions, or denial of service for contract users.

🟢

If Mitigated

No impact if contracts don't use large arrays (>2^46 bytes) or are patched to Vyper 0.3.8+.

🌐 Internet-Facing: HIGH

🏢 Internal Only: LOW

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: HIGH

Exploitation requires specific conditions (large arrays) and understanding of Ethereum smart contract memory layout.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 0.3.8

Vendor Advisory: https://github.com/vyperlang/vyper/security/advisories/GHSA-6m97-7527-mh74

Restart Required: No

Instructions:

1. Update Vyper compiler to version 0.3.8 or later. 2. Recompile all existing smart contracts with the updated compiler. 3. Redeploy affected contracts to the blockchain.

🔧 Temporary Workarounds

Avoid large arrays

all

Modify smart contracts to avoid using arrays larger than 2^46 bytes

🧯 If You Can't Patch

Audit all smart contracts for large array usage and redesign if possible
Implement additional validation and monitoring for contract behavior

🔍 How to Verify

Check if Vulnerable:

Check Vyper compiler version with 'vyper --version'. If version is <0.3.8, check contracts for large array declarations.

Check Version:

vyper --version

Verify Fix Applied:

Verify Vyper version is 0.3.8+ and recompile contracts. Test contract functionality with large array operations.

📡 Detection & Monitoring

Log Indicators:

Failed contract deployments
Unexpected contract behavior with array operations
Gas limit exceeded errors

Network Indicators:

Unusual transaction patterns to affected contracts
Failed contract calls

SIEM Query:

Not applicable - blockchain transactions are public but detection requires monitoring contract behavior

📊 Metadata

CVE ID: CVE-2023-46247

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-193

Published: December 13, 2023

Last Updated: November 21, 2024

🔗 References

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🔗 Related Vulnerabilities

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