CVE-2022-50238
📋 TL;DR
CVE-2022-50238 is a synchronization vulnerability in Microsoft's driver blocklist system where the on-endpoint blocklist doesn't fully match the online recommended block rules. This allows malicious drivers that should be blocked to potentially execute on Windows systems. All Windows systems using the default driver blocklist are affected.
💻 Affected Systems
- Microsoft Windows
⚠️ 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
Attackers could load malicious drivers with kernel-level privileges, enabling complete system compromise, data theft, persistence mechanisms, or disabling security controls.
Likely Case
Targeted attacks by sophisticated threat actors using known vulnerable drivers to bypass security controls and establish persistence on compromised systems.
If Mitigated
With proper WDAC policies applied, the full blocklist is enforced, preventing malicious driver execution and maintaining system integrity.
🎯 Exploit Status
Exploitation requires administrative privileges to load drivers. Attackers would need to first gain elevated access through other means.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Windows updates with synchronized blocklists (monthly updates)
Restart Required: Yes
Instructions:
1. Install latest Windows updates. 2. Ensure Windows Update is configured to receive driver blocklist updates. 3. Restart system if required by updates.
🔧 Temporary Workarounds
Apply WDAC policies with full blocklist
windowsManually apply Windows Defender Application Control policies using the full Microsoft recommended driver block rules
# Use applywdac tool from GitHub
# PowerShell: Apply-WdacPolicy -PolicyPath 'path\to\full_blocklist.xml'
🧯 If You Can't Patch
- Implement strict application control policies to block all unsigned drivers
- Monitor for driver loading events and investigate any suspicious driver installations
🔍 How to Verify
Check if Vulnerable:
Compare on-endpoint driver blocklist with online Microsoft recommended driver block rules using PowerShell or WDAC toolsCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows recent updates and check that WDAC policies are applied with full blocklist📡 Detection & Monitoring
Log Indicators:
- Event ID 3076 in Windows Defender Application Control logs
- Unexpected driver loading events in Security logs
- Driver installation from untrusted sources
Network Indicators:
- Network connections from kernel-mode drivers to suspicious destinations
- Driver downloads from unverified sources
SIEM Query:
EventID=3076 OR (EventID=7045 AND (ImagePath="*.sys" OR ServiceName="Driver"))