CVE-2022-49737
📋 TL;DR
This CVE describes a race condition vulnerability in X.Org X server where the main thread modifies data structures used by the input thread without proper locking. This could allow an attacker to cause memory corruption or potentially execute arbitrary code. Systems running X server with easystroke mouse gestures enabled are affected.
💻 Affected Systems
- X.Org X server
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Arbitrary code execution with the privileges of the X server process (typically root or high-privileged user), leading to complete system compromise.
Likely Case
Denial of service through X server crash or instability, potentially causing loss of graphical session.
If Mitigated
Minor performance impact or no impact if race condition doesn't trigger during normal operation.
🎯 Exploit Status
Exploitation requires precise timing to trigger the race condition and knowledge of memory layout. No public exploits have been documented.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: X server versions after commit dc7cb45482cea6ccec22d117ca0b489500b4d0a0
Vendor Advisory: https://gitlab.freedesktop.org/xorg/xserver/-/issues/1260
Restart Required: Yes
Instructions:
1. Update X server package through your distribution's package manager. 2. For source installations: apply patch from Debian bug report. 3. Restart X server or reboot system.
🔧 Temporary Workarounds
Disable easystroke mouse gestures
allPrevent client applications from using easystroke mouse gestures to avoid triggering the race condition.
Configure client applications to not use easystroke functionality
Remove or disable easystroke packages if installed
🧯 If You Can't Patch
- Restrict local user access to systems running vulnerable X server versions
- Monitor for X server crashes or unusual behavior indicating potential exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check X server version with 'Xorg -version' and verify if between 20.11 and 21.1.16 inclusive.Check Version:
Xorg -version 2>&1 | grep -i 'x.org x server'Verify Fix Applied:
Verify X server version is newer than 21.1.16 or check if patch commit dc7cb45482cea6ccec22d117ca0b489500b4d0a0 is applied.📡 Detection & Monitoring
Log Indicators:
- X server segmentation faults or crashes in system logs
- Unexpected X server restarts
- Error messages related to input devices or easystroke
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
search 'Xorg' AND ('segmentation fault' OR 'crash' OR 'SIGSEGV') in system logs🔗 References
- https://bugs.debian.org/cgi-bin/bugreport.cgi?att=1;bug=1081338;filename=dix-Hold-input-lock-for-AttachDevice.patch;msg=5
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1081338
- https://gitlab.freedesktop.org/xorg/xserver/-/commit/dc7cb45482cea6ccec22d117ca0b489500b4d0a0
- https://gitlab.freedesktop.org/xorg/xserver/-/issues/1260
- https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1081338
