CVE-2013-7087
📋 TL;DR
CVE-2013-7087 is a heap memory corruption vulnerability in ClamAV's WWPack file unpacking module. Attackers can exploit this by crafting malicious WWPack archives to execute arbitrary code or cause denial of service. All systems running ClamAV versions before 0.97.7 are affected.
💻 Affected Systems
- ClamAV
📦 What is this software?
Clamav by Clamav
Fedora by Fedoraproject
Fedora by Fedoraproject
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with root/system privileges leading to complete system compromise, data theft, and persistent backdoor installation.
Likely Case
Denial of service through antivirus service crashes, potentially disrupting email scanning and file processing systems.
If Mitigated
Limited impact with proper network segmentation and minimal privileges, though service disruption remains possible.
🎯 Exploit Status
Proof-of-concept exploit code has been publicly available since 2013. The vulnerability requires only a malicious WWPack file to trigger.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.97.7 and later
Vendor Advisory: https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2013-7087
Restart Required: Yes
Instructions:
1. Stop ClamAV service: 'systemctl stop clamav' or equivalent. 2. Update ClamAV: 'apt-get update && apt-get install clamav' (Debian/Ubuntu) or 'yum update clamav' (RHEL/CentOS). 3. Update virus definitions: 'freshclam'. 4. Restart ClamAV service: 'systemctl start clamav'.
🔧 Temporary Workarounds
Disable WWPack unpacking
linuxTemporarily disable WWPack archive scanning in ClamAV configuration
Edit /etc/clamav/clamd.conf or equivalent
Add line: 'ArchiveBlockEncrypted no'
Restart clamd: 'systemctl restart clamav'
🧯 If You Can't Patch
- Network segmentation: Isolate ClamAV servers from critical systems
- Implement strict file upload restrictions and sandboxing for untrusted file processing
🔍 How to Verify
Check if Vulnerable:
Run: 'clamscan --version' and check if version is below 0.97.7Check Version:
clamscan --version | head -1Verify Fix Applied:
Run: 'clamscan --version' and confirm version is 0.97.7 or higher📡 Detection & Monitoring
Log Indicators:
- ClamAV service crashes in system logs
- Repeated clamd process restarts
- Error messages mentioning WWPack or heap corruption
Network Indicators:
- Unusual outbound connections from ClamAV servers
- Large WWPack files being processed
SIEM Query:
source="clamav.log" AND ("crash" OR "segmentation fault" OR "heap corruption")🔗 References
- http://security.gentoo.org/glsa/glsa-201405-08.xml
- http://www.openwall.com/lists/oss-security/2013/12/13/1
- http://www.securityfocus.com/bid/58546
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2013-7087
- https://security-tracker.debian.org/tracker/CVE-2013-7087
- http://security.gentoo.org/glsa/glsa-201405-08.xml
- http://www.openwall.com/lists/oss-security/2013/12/13/1
- http://www.securityfocus.com/bid/58546
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2013-7087
- https://security-tracker.debian.org/tracker/CVE-2013-7087
