CVE-2007-0899
📋 TL;DR
CVE-2007-0899 is a heap overflow vulnerability in ClamAV's libclamav/fsg.c that allows remote attackers to execute arbitrary code by sending specially crafted files. This affects systems running ClamAV antivirus software before version 0.100.0. The vulnerability is particularly dangerous as it can be exploited through normal antivirus scanning operations.
💻 Affected Systems
- ClamAV
📦 What is this software?
Clamav by Clamav
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with system-level privileges, potentially leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Remote code execution leading to malware installation, backdoor creation, or system disruption through antivirus process crashes.
If Mitigated
Denial of service through antivirus process crashes if exploit fails or is blocked by additional security controls.
🎯 Exploit Status
The vulnerability is in file parsing code, making exploitation relatively straightforward for attackers with knowledge of heap overflow techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.100.0 and later
Vendor Advisory: https://security-tracker.debian.org/tracker/CVE-2007-0899
Restart Required: Yes
Instructions:
1. Stop ClamAV services. 2. Update ClamAV to version 0.100.0 or later using your distribution's package manager. 3. Update virus definitions. 4. Restart ClamAV services.
🔧 Temporary Workarounds
Disable FSG file scanning
allTemporarily disable scanning of FSG-packed files which trigger the vulnerability
clamscan --exclude-type=fsg
Configure ClamAV to exclude FSG file types in clamd.conf
🧯 If You Can't Patch
- Implement network segmentation to isolate systems running vulnerable ClamAV versions
- Deploy additional security controls like application whitelisting or runtime protection to prevent code execution
🔍 How to Verify
Check if Vulnerable:
Run 'clamscan --version' and check if version is below 0.100.0Check Version:
clamscan --version | grep ClamAVVerify Fix Applied:
Run 'clamscan --version' and confirm version is 0.100.0 or higher, then test scanning known safe files📡 Detection & Monitoring
Log Indicators:
- ClamAV process crashes
- Memory access violation errors in system logs
- Unusual file scanning failures
Network Indicators:
- Unusual outbound connections from ClamAV processes
- File uploads to systems with ClamAV scanning
SIEM Query:
process_name:"clam" AND (event_type:"crash" OR error_code:"segmentation_fault")