CVE-2023-35632
📋 TL;DR
This vulnerability in the Windows Ancillary Function Driver for WinSock allows an attacker to gain SYSTEM-level privileges by exploiting an integer overflow. It affects Windows systems where an authenticated attacker can execute code locally.
💻 Affected Systems
- Microsoft Windows
📦 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
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM privileges, enabling installation of malware, data theft, and lateral movement across the network.
Likely Case
Local privilege escalation from a standard user account to SYSTEM, allowing attackers to bypass security controls and maintain persistence.
If Mitigated
Limited impact if proper patch management and least privilege principles are enforced, restricting initial access.
🎯 Exploit Status
Requires local authenticated access and knowledge of exploitation techniques for integer overflow vulnerabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply the November 2023 security updates from Microsoft
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-35632
Restart Required: Yes
Instructions:
1. Open Windows Update settings
2. Check for updates
3. Install all available security updates
4. Restart the system when prompted
🔧 Temporary Workarounds
Restrict local user privileges
windowsApply least privilege principles to limit what authenticated users can do on systems
🧯 If You Can't Patch
- Implement strict access controls and network segmentation to limit lateral movement
- Monitor for privilege escalation attempts and unusual SYSTEM-level activity
🔍 How to Verify
Check if Vulnerable:
Check if November 2023 security updates are installed via Windows Update history or systeminfo commandCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB5032190 (or later) is installed for Windows 10/11, or equivalent Server updates📡 Detection & Monitoring
Log Indicators:
- Event ID 4688 with parent process anomalies
- Unexpected SYSTEM privilege acquisition
- Process creation from unusual locations
Network Indicators:
- Lateral movement attempts following local privilege escalation
SIEM Query:
EventID=4688 AND NewProcessName="*" AND TokenElevationType=%%1938