CVE-2023-20032
📋 TL;DR
A heap buffer overflow vulnerability in ClamAV's HFS+ partition file parser allows remote unauthenticated attackers to execute arbitrary code or cause denial of service. This affects ClamAV versions 1.0.0 and earlier, 0.105.1 and earlier, and 0.103.7 and earlier. Any system using vulnerable ClamAV versions for file scanning is at risk.
💻 Affected Systems
- ClamAV
📦 What is this software?
Clamav by Clamav
Clamav by Clamav
Clamav by Clamav
Clamav by Clamav
Clamav by Clamav
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with ClamAV process privileges leading to full system compromise
Likely Case
Denial of service through process crashes disrupting scanning services
If Mitigated
Limited impact if proper network segmentation and least privilege are implemented
🎯 Exploit Status
Vulnerability is remotely exploitable without authentication via crafted HFS+ files
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.1, 0.105.2, 0.103.8
Vendor Advisory: https://blog.clamav.net/
Restart Required: Yes
Instructions:
1. Update ClamAV to patched version 2. Restart ClamAV service 3. Verify update with clamscan --version
🔧 Temporary Workarounds
Disable HFS+ file scanning
allConfigure ClamAV to skip HFS+ partition files
Add 'ScanHFSPlus no' to clamd.conf
Network segmentation
allIsolate ClamAV scanning systems from critical networks
🧯 If You Can't Patch
- Implement strict file upload controls to prevent HFS+ files from reaching scanners
- Run ClamAV with minimal privileges and in isolated containers
🔍 How to Verify
Check if Vulnerable:
Run 'clamscan --version' and check if version is in affected rangeCheck Version:
clamscan --versionVerify Fix Applied:
Confirm version is 1.0.1, 0.105.2, or 0.103.8 or later📡 Detection & Monitoring
Log Indicators:
- ClamAV process crashes
- Unusual memory usage patterns in ClamAV
Network Indicators:
- Unexpected HFS+ file submissions to scanning endpoints
SIEM Query:
source="clamav" AND (event="crash" OR event="segfault")