CVE-2025-21375
📋 TL;DR
This vulnerability in the Kernel Streaming WOW Thunk Service Driver allows attackers to escalate privileges from a lower-privileged account to SYSTEM level. It affects Windows systems with the vulnerable driver component. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- Microsoft Windows
📦 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 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with SYSTEM privileges, enabling installation of malware, data theft, and complete control over the affected system.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install persistent backdoors, or access sensitive system resources.
If Mitigated
Limited impact if proper access controls, least privilege principles, and endpoint protection are implemented.
🎯 Exploit Status
Requires local access and some technical knowledge. No public exploit code known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: To be determined from Microsoft's monthly security updates
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-21375
Restart Required: No
Instructions:
1. Check Microsoft Security Update Guide for CVE-2025-21375. 2. Apply the appropriate Windows security update for your version. 3. Verify the update was successful.
🔧 Temporary Workarounds
Restrict driver loading
WindowsConfigure Windows to only load signed drivers to prevent unauthorized driver exploitation
bcdedit /set testsigning off
bcdedit /set nointegritychecks off
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles
- 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 mentioned in Microsoft's advisoryCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the security update is installed via Windows Update or by checking system version📡 Detection & Monitoring
Log Indicators:
- Event ID 4697: Service installation
- Suspicious driver loading events
- Privilege escalation attempts in security logs
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
EventID=4697 OR (EventID=4688 AND NewProcessName contains "cmd.exe" OR "powershell.exe") | where ParentProcessName contains "services.exe"