CVE-2025-29824
📋 TL;DR
This is a local privilege escalation vulnerability in the Windows Common Log File System Driver. An authenticated attacker can exploit a use-after-free flaw to gain SYSTEM-level privileges on affected Windows systems. This affects Windows systems with the vulnerable driver component.
💻 Affected Systems
- Windows Common Log File System Driver
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1507 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains full SYSTEM privileges, enabling complete system compromise, persistence installation, credential theft, and lateral movement across the network.
Likely Case
Local attacker elevates from standard user to SYSTEM privileges to bypass security controls, install malware, or access protected resources.
If Mitigated
With proper access controls and monitoring, exploitation attempts can be detected and contained before significant damage occurs.
🎯 Exploit Status
Exploitation requires local authenticated access. The vulnerability is in CISA's Known Exploited Vulnerabilities catalog, indicating active exploitation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-29824
Restart Required: Yes
Instructions:
1. Apply the latest Windows security updates from Microsoft. 2. Install the specific KB patch for your Windows version. 3. Restart the system as required.
🔧 Temporary Workarounds
Disable CLFS driver
windowsDisable the vulnerable Common Log File System driver component
sc config clfs start= disabled
sc stop clfs
Restrict driver loading
windowsImplement driver signature enforcement policies
bcdedit /set nointegritychecks off
bcdedit /set testsigning off
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles to limit local user access
- Deploy endpoint detection and response (EDR) solutions to monitor for privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for the specific KB patch or use Microsoft's security update verification toolsCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the patch is installed via Windows Update history or by checking system file versions📡 Detection & Monitoring
Log Indicators:
- Event ID 4697: Service installation attempts
- Suspicious process creation with SYSTEM privileges from non-admin users
- Driver loading events related to CLFS
Network Indicators:
- Unusual outbound connections from newly privileged processes
- Lateral movement attempts following local privilege escalation
SIEM Query:
EventID=4697 OR (ProcessName="cmd.exe" OR ProcessName="powershell.exe") AND IntegrityLevel="System" AND UserName!="SYSTEM"🔗 References
- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-29824
- https://www.vicarius.io/vsociety/posts/cve-2025-29824-windows-common-log-file-system-driver-elevation-of-privilege-vulnerability-detection-script
- https://www.vicarius.io/vsociety/posts/cve-2025-29824-windows-common-log-file-system-driver-elevation-of-privilege-vulnerability-mitigation-script
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-29824
