CVE-2011-3630
📋 TL;DR
CVE-2011-3630 is a stack-based buffer overflow vulnerability in the Hardlink utility that allows remote attackers to execute arbitrary code by tricking users into processing specially crafted directory trees. This affects users who run Hardlink on untrusted directory structures. The vulnerability requires user interaction to trigger.
💻 Affected Systems
- Hardlink
📦 What is this software?
Hardlink by Hardlink Project
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with the privileges of the user running Hardlink, potentially leading to full system compromise if run with elevated privileges.
Likely Case
Application crash (denial of service) when processing malicious directory structures, with potential for limited code execution in specific scenarios.
If Mitigated
No impact if Hardlink is not used or if users only process trusted directory structures.
🎯 Exploit Status
Exploitation requires user to run Hardlink on malicious directory structure. Proof of concept available in security advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.1.2 and later
Vendor Advisory: https://access.redhat.com/security/cve/cve-2011-3630
Restart Required: No
Instructions:
1. Check current Hardlink version: hardlink --version
2. Update via package manager: sudo apt-get update && sudo apt-get install hardlink (Debian/Ubuntu) or sudo yum update hardlink (RHEL/CentOS)
3. Verify update: hardlink --version should show 0.1.2 or higher
🔧 Temporary Workarounds
Remove Hardlink
linuxUninstall Hardlink if not needed
sudo apt-get remove hardlink
sudo yum remove hardlink
Restrict Hardlink Usage
linuxLimit Hardlink execution to trusted users only
sudo chmod 750 /usr/bin/hardlink
sudo chown root:trustedgroup /usr/bin/hardlink
🧯 If You Can't Patch
- Do not run Hardlink on untrusted directory structures
- Implement strict access controls on directories that Hardlink processes
🔍 How to Verify
Check if Vulnerable:
Run: hardlink --version | grep -q '^hardlink 0\.1\.[01]\|^hardlink 0\.0\.' && echo 'VULNERABLE' || echo 'NOT VULNERABLE'Check Version:
hardlink --versionVerify Fix Applied:
Run: hardlink --version | grep -q '^hardlink 0\.1\.[2-9]\|^hardlink [1-9]' && echo 'PATCHED' || echo 'STILL VULNERABLE'📡 Detection & Monitoring
Log Indicators:
- Segmentation fault or crash logs from Hardlink process
- Unexpected Hardlink execution on deep directory structures
Network Indicators:
- N/A - local exploitation only
SIEM Query:
process.name:"hardlink" AND (event.action:"segmentation_fault" OR event.outcome:"failure")🔗 References
- https://access.redhat.com/security/cve/cve-2011-3630
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=645516
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-3630
- https://security-tracker.debian.org/tracker/CVE-2011-3630
- https://www.openwall.com/lists/oss-security/2011/10/20/6
- https://access.redhat.com/security/cve/cve-2011-3630
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=645516
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-3630
- https://security-tracker.debian.org/tracker/CVE-2011-3630
- https://www.openwall.com/lists/oss-security/2011/10/20/6
