CVE-2006-0062
📋 TL;DR
CVE-2006-0062 is a privilege escalation vulnerability in xlockmore 5.13 that allows bypassing screen lock protection when FVWM window manager switches to the same virtual desktop as a new Gaim instant messaging window. This affects Linux/Unix systems using xlockmore with FVWM and Gaim running concurrently. The vulnerability enables unauthorized access to locked sessions.
💻 Affected Systems
- xlockmore
📦 What is this software?
Xlockmore by Sillycycle
⚠️ Risk & Real-World Impact
Worst Case
An attacker with physical or remote desktop access could bypass screen lock and gain unauthorized access to the user's session, potentially accessing sensitive data, executing commands, or installing malware.
Likely Case
Local attackers or users with brief physical access could bypass screen lock to access the victim's desktop session and applications.
If Mitigated
With proper access controls and monitoring, impact is limited to temporary unauthorized access that can be detected and terminated.
🎯 Exploit Status
Exploitation requires local access to the graphical environment and specific software configuration. The bug report includes demonstration details.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: xlockmore 5.14 and later
Vendor Advisory: https://security-tracker.debian.org/tracker/CVE-2006-0062
Restart Required: Yes
Instructions:
1. Update xlockmore to version 5.14 or later using your distribution's package manager. 2. For Debian/Ubuntu: sudo apt-get update && sudo apt-get install xlockmore. 3. Restart the X session or reboot the system.
🔧 Temporary Workarounds
Disable FVWM or Gaim
linuxPrevent the vulnerable software combination by disabling either FVWM window manager or Gaim instant messaging client.
sudo systemctl stop gaim
sudo apt-get remove --purge gaim
Switch to alternative window manager like GNOME or KDE
Use alternative screen locker
linuxReplace xlockmore with a different screen locking utility that is not vulnerable.
sudo apt-get install xscreensaver
sudo apt-get remove --purge xlockmore
🧯 If You Can't Patch
- Implement strict physical access controls to prevent unauthorized users from approaching workstations
- Configure automatic session logout after inactivity periods shorter than typical screen lock durations
🔍 How to Verify
Check if Vulnerable:
Check xlockmore version: xlock -version 2>&1 | grep -i version. If output shows 5.13 and system uses FVWM with Gaim, it's vulnerable.Check Version:
xlock -version 2>&1 | grep -i version || dpkg -l | grep xlockmore || rpm -qa | grep xlockmoreVerify Fix Applied:
After update, verify version: xlock -version 2>&1 | grep -i version. Should show 5.14 or higher.📡 Detection & Monitoring
Log Indicators:
- Multiple rapid screen lock/unlock events
- Unexpected desktop switching in FVWM logs
- Gaim window creation events coinciding with screen lock bypass
Network Indicators:
- N/A - local attack only
SIEM Query:
source="x11_logs" AND (event="screen_lock_bypass" OR (process="xlock" AND status="unexpected_unlock"))