CVE-2025-55335
📋 TL;DR
CVE-2025-55335 is a use-after-free vulnerability in Windows NTFS that allows local attackers to execute arbitrary code with elevated privileges. This affects Windows systems with NTFS file systems. Attackers must already have local access to exploit this vulnerability.
💻 Affected Systems
- Windows operating systems
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1607 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
Windows 11 25h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM/administrator privileges, enabling persistence, lateral movement, and data exfiltration.
Likely Case
Local privilege escalation from a standard user account to administrator/SYSTEM level, allowing installation of malware, disabling security controls, or accessing protected data.
If Mitigated
Limited impact if proper privilege separation, application control, and endpoint protection are in place, though local privilege escalation remains possible.
🎯 Exploit Status
Exploitation requires local access and understanding of NTFS internals; use-after-free vulnerabilities typically require precise timing and memory manipulation.
🛠️ 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-2025-55335
Restart Required: Yes
Instructions:
1. Open Windows Update Settings
2. Click 'Check for updates'
3. Install all available security updates
4. Restart system when prompted
🔧 Temporary Workarounds
Restrict local access
allLimit physical and remote local access to vulnerable systems through access controls and network segmentation.
Enable exploit protection
windowsUse Windows Defender Exploit Guard or similar solutions to mitigate memory corruption attacks.
Set-ProcessMitigation -System -Enable DEP,ASLR,CFG
🧯 If You Can't Patch
- Implement strict privilege separation and least privilege principles
- Deploy endpoint detection and response (EDR) solutions to detect privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for missing security patches related to CVE-2025-55335Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB patch is installed via 'wmic qfe list' or 'Get-Hotfix' in PowerShell📡 Detection & Monitoring
Log Indicators:
- Unusual process creation with SYSTEM privileges
- Failed privilege escalation attempts in security logs
- Suspicious access to NTFS driver components
Network Indicators:
- Lateral movement following local compromise
- Unusual authentication patterns from previously compromised hosts
SIEM Query:
EventID=4688 AND NewProcessName="*" AND SubjectUserName!="SYSTEM" AND TokenElevationType="%%1938"