CVE-2020-1207
📋 TL;DR
This is a Windows kernel-mode driver vulnerability that allows local attackers to escalate privileges from a lower-privileged account to SYSTEM level. It affects Windows operating systems when the Win32k driver improperly handles memory objects. Attackers need local access to exploit 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 7 by Microsoft
Windows 8.1 by Microsoft
Windows Rt 8.1 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM privileges, enabling installation of malware, data theft, and persistence mechanisms.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install additional malware, or access restricted system resources.
If Mitigated
Limited impact if proper access controls and privilege separation are implemented, though successful exploitation still grants elevated privileges.
🎯 Exploit Status
Exploit requires local access and some technical knowledge. Proof-of-concept code has been published by security researchers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: May 2020 security updates (KB4556799 for Windows 10 1903/1909)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1207
Restart Required: Yes
Instructions:
1. Apply May 2020 Windows security updates via Windows Update. 2. For enterprise environments, deploy through WSUS or SCCM. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Restrict local user privileges
windowsLimit local user accounts to standard user privileges to reduce attack surface
Enable Windows Defender Exploit Guard
windowsUse exploit protection to mitigate kernel exploits
🧯 If You Can't Patch
- Implement strict access controls and limit local administrative privileges
- Deploy application whitelisting to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check Windows version and if May 2020 security updates are installed. Vulnerable systems will be on Windows 10 1903/1909 without KB4556799.Check Version:
winver or systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB4556799 is installed via 'wmic qfe list' or 'Get-Hotfix -Id KB4556799' in PowerShell📡 Detection & Monitoring
Log Indicators:
- Windows Security Event ID 4688 (process creation) showing privilege escalation patterns
- Unexpected SYSTEM privilege processes from non-admin users
Network Indicators:
- Not network exploitable - local privilege escalation only
SIEM Query:
EventID=4688 AND NewProcessName="*" AND SubjectUserName!="SYSTEM" AND TokenElevationType="%%1938"