CVE-2025-55339
📋 TL;DR
This vulnerability allows an authenticated attacker to read memory outside intended bounds in Windows NDIS (Network Driver Interface Specification), potentially leading to local privilege escalation. It affects Windows systems with vulnerable NDIS implementations, requiring an attacker to already have some level of access to the target system.
💻 Affected Systems
- Windows NDIS
📦 What is this software?
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
An attacker with initial user privileges could exploit this to gain SYSTEM-level privileges, potentially taking full control of the affected system and accessing sensitive data or installing persistent malware.
Likely Case
An authenticated attacker with standard user privileges could elevate to administrator or SYSTEM privileges, enabling them to bypass security controls, install software, or access protected resources.
If Mitigated
With proper access controls and least privilege principles, the impact is limited as attackers would need initial access and the vulnerability only enables local privilege escalation, not remote code execution.
🎯 Exploit Status
Exploitation requires authenticated access and understanding of Windows kernel memory structures. The out-of-bounds read could be leveraged with other vulnerabilities for full 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-2025-55339
Restart Required: Yes
Instructions:
1. Apply the latest Windows security updates from Microsoft. 2. For enterprise environments, deploy updates through WSUS, SCCM, or Intune. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Restrict user privileges
windowsImplement least privilege access controls to limit the impact if exploitation occurs
Network segmentation
allSegment critical systems to limit lateral movement if privilege escalation occurs
🧯 If You Can't Patch
- Implement strict access controls and limit administrative privileges
- Monitor for suspicious privilege escalation attempts and implement application allowlisting
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for the specific KB patch mentioned in Microsoft's advisory or use systeminfo command to check OS build versionCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the security update is installed via Windows Update history or by checking the OS build version against patched versions in Microsoft's advisory📡 Detection & Monitoring
Log Indicators:
- Windows Security Event ID 4688 (process creation) showing unexpected privilege escalation
- Sysmon Event ID 10 (process access) showing unusual access patterns to privileged processes
Network Indicators:
- Unusual outbound connections from systems after privilege escalation
SIEM Query:
EventID=4688 AND NewProcessName="*" AND TokenElevationType="%%1936" OR TokenElevationType="%%1937"