CVE-2025-27735
📋 TL;DR
This vulnerability allows an authorized attacker with local access to bypass security features in Windows Virtualization-Based Security (VBS) Enclave by exploiting insufficient data authenticity verification. It affects Windows systems with VBS enabled, primarily impacting enterprise environments using virtualization-based security features.
💻 Affected Systems
- Windows Operating System
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1507 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1607 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 1809 by Microsoft
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
An attacker could bypass VBS security controls to access protected memory regions, potentially compromising sensitive data or credentials protected by the enclave.
Likely Case
Local privilege escalation or bypass of security boundaries within the VBS environment, allowing unauthorized access to protected resources.
If Mitigated
With proper access controls and monitoring, impact is limited to the local system and doesn't provide network access or remote exploitation capabilities.
🎯 Exploit Status
Requires authorized local access and knowledge of VBS internals. No public exploits available as of advisory publication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-27735
Restart Required: Yes
Instructions:
1. Open Windows Update Settings 2. Check for updates 3. Install all available security updates 4. Restart system when prompted
🔧 Temporary Workarounds
Disable VBS
windowsDisable Virtualization-Based Security if not required for your security posture
reg add "HKLM\SYSTEM\CurrentControlSet\Control\DeviceGuard" /v "EnableVirtualizationBasedSecurity" /t REG_DWORD /d 0 /f
Restart required
🧯 If You Can't Patch
- Implement strict local access controls and privilege management
- Enable enhanced monitoring for VBS-related activities and memory access patterns
🔍 How to Verify
Check if Vulnerable:
Check if VBS is enabled via System Information (msinfo32.exe) or PowerShell: Get-ComputerInfo -Property "DeviceGuard*"Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history for the specific KB patch and confirm VBS is functioning normally📡 Detection & Monitoring
Log Indicators:
- Unusual VBS enclave access patterns
- Failed VBS integrity checks
- Security feature bypass attempts in Windows Security logs
Network Indicators:
- None - this is a local vulnerability
SIEM Query:
EventID=4688 OR EventID=4689 with process names related to VBS or hypervisor components