CVE-2019-1185
📋 TL;DR
CVE-2019-1185 is a stack corruption vulnerability in Windows Subsystem for Linux that allows local attackers to execute arbitrary code with elevated privileges. This affects Windows systems with WSL enabled where an authenticated user could run a malicious application. The vulnerability enables privilege escalation from a standard user account to higher system permissions.
💻 Affected Systems
- Windows Subsystem for Linux (WSL)
📦 What is this software?
Windows 10 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise where an attacker gains SYSTEM-level privileges, installs persistent malware, accesses sensitive data, and pivots to other systems.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install additional malware, or access restricted system resources.
If Mitigated
Limited impact with proper patch management and restricted user privileges, though local authenticated users could still attempt exploitation.
🎯 Exploit Status
Exploitation requires local authenticated access and knowledge of WSL internals. The vulnerability involves stack corruption which requires careful memory manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Windows 10 version 1903 KB4512941 and later updates
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1185
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. 5. Verify the update was applied successfully.
🔧 Temporary Workarounds
Disable Windows Subsystem for Linux
windowsDisables WSL feature entirely, removing the vulnerable component
dism.exe /online /disable-feature /featurename:Microsoft-Windows-Subsystem-Linux
Restrict user privileges
allImplement least privilege principle to limit potential damage from successful exploitation
🧯 If You Can't Patch
- Disable Windows Subsystem for Linux feature if not required
- Implement strict access controls and monitor for suspicious privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check Windows version and if WSL is enabled. Vulnerable if Windows 10 version 1903 or earlier with WSL installed.Check Version:
winverVerify Fix Applied:
Verify Windows build number is 18362.356 or later for Windows 10 version 1903, or check that KB4512941 or later security update is installed.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation with elevated privileges from WSL processes
- Security event logs showing privilege escalation attempts
Network Indicators:
- Not applicable - local vulnerability
SIEM Query:
EventID=4688 AND NewProcessName contains *wsl* AND SubjectUserName != SYSTEM