CVE-2014-8140
📋 TL;DR
CVE-2014-8140 is a heap-based buffer overflow vulnerability in Info-ZIP UnZip that allows remote attackers to execute arbitrary code by tricking users into testing a malicious zip file with the '-t' command argument. This affects systems running UnZip 6.0 and earlier versions. The vulnerability can lead to complete system compromise if exploited successfully.
💻 Affected Systems
- Info-ZIP UnZip
- Various Linux distributions with unzip package
- Third-party applications embedding unzip functionality
📦 What is this software?
Unzip by Unzip Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the user running unzip, potentially leading to full system compromise, data theft, or installation of persistent malware.
Likely Case
Local privilege escalation or arbitrary code execution when users process untrusted zip files, particularly in automated scripts or batch processing environments.
If Mitigated
Denial of service or application crash if exploit fails, with limited impact if proper sandboxing and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires the victim to run 'unzip -t' on a malicious zip file. Public proof-of-concept code exists, making weaponization likely in targeted attacks.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: UnZip 6.10 and later
Vendor Advisory: https://access.redhat.com/errata/RHSA-2015:0700
Restart Required: No
Instructions:
1. Update unzip package using your distribution's package manager. 2. For Red Hat/CentOS: 'yum update unzip'. 3. For Debian/Ubuntu: 'apt-get update && apt-get install unzip'. 4. For source installations: Download and compile UnZip 6.10 or later from official sources.
🔧 Temporary Workarounds
Disable unzip -t functionality
linuxRemove or restrict execute permissions on unzip binary or create wrapper script that blocks -t argument
chmod a-x /usr/bin/unzip
mv /usr/bin/unzip /usr/bin/unzip.disabled
Use alternative zip utilities
linuxReplace unzip with patched alternatives like 7zip or patched versions
apt-get install p7zip-full
yum install p7zip
🧯 If You Can't Patch
- Implement strict input validation for zip files, rejecting malformed archives
- Run unzip in sandboxed environments with minimal privileges and no network access
🔍 How to Verify
Check if Vulnerable:
Check unzip version: 'unzip -v | head -1' and verify if version is 6.0 or earlierCheck Version:
unzip -v | head -1Verify Fix Applied:
Confirm version is 6.10 or later: 'unzip -v | head -1' should show version 6.10+📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or crash logs from unzip process
- Unusual command-line arguments to unzip with -t flag
- Failed zip file tests with suspicious file names
Network Indicators:
- Downloads of zip files followed by unzip -t commands
- Unusual outbound connections after zip processing
SIEM Query:
process_name:"unzip" AND command_line:"*-t*" AND (event_type:"process_crash" OR exit_code:139)🔗 References
- http://www.ocert.org/advisories/ocert-2014-011.html
- http://www.securitytracker.com/id/1031433
- https://access.redhat.com/errata/RHSA-2015:0700
- https://bugzilla.redhat.com/show_bug.cgi?id=1174851
- http://www.ocert.org/advisories/ocert-2014-011.html
- http://www.securitytracker.com/id/1031433
- https://access.redhat.com/errata/RHSA-2015:0700
- https://bugzilla.redhat.com/show_bug.cgi?id=1174851
