CVE-2025-54093
📋 TL;DR
A Time-of-Check Time-of-Use (TOCTOU) race condition vulnerability in Windows TCP/IP stack allows authenticated local attackers to elevate privileges by exploiting timing inconsistencies between permission checks and resource usage. This affects Windows systems with the vulnerable TCP/IP implementation. 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
Complete system compromise where an authenticated attacker gains SYSTEM/administrator privileges, enabling installation of malware, data theft, lateral movement, and persistence establishment.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, access restricted resources, and perform administrative actions from a standard user account.
If Mitigated
Limited impact with proper access controls, monitoring, and network segmentation preventing lateral movement even if privilege escalation occurs.
🎯 Exploit Status
TOCTOU race conditions require precise timing and may be difficult to reliably exploit. Requires local authenticated access. No public exploit code available at this time.
🛠️ 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-2025-54093
Restart Required: Yes
Instructions:
1. Open Windows Update Settings
2. Click 'Check for updates'
3. Install all available security updates
4. Restart the system when prompted
5. Verify update installation in Update History
🔧 Temporary Workarounds
Restrict Local Access
windowsLimit local interactive logon to essential personnel only
Implement Least Privilege
windowsEnsure users operate with minimal necessary privileges
🧯 If You Can't Patch
- Implement strict access controls and monitor for privilege escalation attempts
- Segment networks to limit lateral movement if exploitation occurs
🔍 How to Verify
Check if Vulnerable:
Check Windows Update History for missing security patches related to CVE-2025-54093Check Version:
wmic qfe list | findstr KBVerify Fix Applied:
Verify the specific KB patch from Microsoft Security Update Guide is installed📡 Detection & Monitoring
Log Indicators:
- Unexpected privilege escalation events in Windows Security logs
- Suspicious process creation with elevated privileges
- Failed privilege escalation attempts
Network Indicators:
- Unusual outbound connections from previously low-privilege accounts
- Lateral movement attempts following local exploitation
SIEM Query:
EventID=4672 AND SubjectUserName!=SYSTEM AND NewProcessName contains suspicious patterns