CVE-2025-62220
📋 TL;DR
A heap-based buffer overflow vulnerability in Windows Subsystem for Linux GUI allows remote attackers to execute arbitrary code on affected systems. This affects Windows systems running WSLg with network exposure. Attackers can exploit this without authentication over the network.
💻 Affected Systems
- Windows Subsystem for Linux GUI (WSLg)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with remote code execution leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Remote code execution leading to lateral movement within the network, credential harvesting, and data exfiltration.
If Mitigated
Limited impact if network segmentation and proper access controls prevent exploitation attempts.
🎯 Exploit Status
Heap overflow vulnerabilities typically require some exploit development but are frequently weaponized once details become public.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Latest Windows security update addressing CVE-2025-62220
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-62220
Restart Required: Yes
Instructions:
1. Open Windows Update settings
2. Click 'Check for updates'
3. Install all available security updates
4. Restart the system when prompted
🔧 Temporary Workarounds
Disable WSLg Network Access
windowsBlock network access to WSLg components using Windows Firewall
New-NetFirewallRule -DisplayName "Block WSLg" -Direction Inbound -Program "%SystemRoot%\System32\wslg.exe" -Action Block
Disable WSL Feature
windowsCompletely disable Windows Subsystem for Linux if not required
wsl --unregister
dism.exe /online /disable-feature /featurename:Microsoft-Windows-Subsystem-Linux
🧯 If You Can't Patch
- Implement strict network segmentation to isolate systems with WSLg from untrusted networks
- Deploy application control policies to prevent execution of unauthorized binaries
🔍 How to Verify
Check if Vulnerable:
Check if WSLg is installed and network-accessible. Review Windows Update history for missing security patches.Check Version:
wsl --versionVerify Fix Applied:
Verify Windows Update shows the latest security update installed and system has been restarted.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from wslg.exe
- Network connections to WSLg ports from unexpected sources
- Memory access violations in system logs
Network Indicators:
- Unexpected network traffic to WSLg service ports
- Exploit kit traffic patterns targeting CVE-2025-62220
SIEM Query:
Process Creation where Image contains 'wslg' AND Parent Process not in ('explorer.exe', 'cmd.exe')