CVE-2020-1152
📋 TL;DR
This Windows privilege escalation vulnerability allows attackers who can run code on a system to gain elevated privileges by exploiting improper handling in the Win32k.sys kernel driver. It affects Windows systems where an attacker has local access. Microsoft has patched this vulnerability.
💻 Affected Systems
- Microsoft Windows
📦 What is this software?
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 8.1 by Microsoft
Windows Rt 8.1 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Attacker gains SYSTEM-level privileges, enabling complete system compromise, persistence, credential theft, and lateral movement.
Likely Case
Local attacker escalates from standard user to administrator privileges, enabling installation of malware, disabling security controls, or accessing sensitive data.
If Mitigated
With proper access controls and least privilege principles, impact is limited to the compromised user's scope.
🎯 Exploit Status
Requires local access and ability to execute specially crafted code. No public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: May 2020 security updates (KB4556799 for 1903/1909)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1152
Restart Required: Yes
Instructions:
1. Apply May 2020 Windows security updates via Windows Update. 2. For enterprise: Deploy KB4556799 through WSUS or SCCM. 3. Restart system after installation.
🔧 Temporary Workarounds
Restrict local code execution
windowsImplement application whitelisting to prevent unauthorized script/application execution
Use AppLocker or Windows Defender Application Control policies
🧯 If You Can't Patch
- Implement strict least privilege - ensure users run with minimal necessary permissions
- Monitor for suspicious process creation and privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows version and if May 2020 updates are installed via winver or systeminfoCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB4556799 is installed in Installed Updates or via PowerShell: Get-HotFix -Id KB4556799📡 Detection & Monitoring
Log Indicators:
- Event ID 4688: New process creation with elevated privileges
- Suspicious Win32k.sys calls in kernel logs
Network Indicators:
- None - local privilege escalation only
SIEM Query:
EventID=4688 AND NewProcessName contains suspicious.exe AND TokenElevationType=%%1938