CVE-2025-54091
📋 TL;DR
An integer overflow vulnerability in Windows Hyper-V allows authenticated attackers to escalate privileges on the local system. This affects Windows systems running Hyper-V virtualization. Attackers need valid credentials on the host to exploit this vulnerability.
💻 Affected Systems
- Windows Hyper-V
📦 What is this software?
Windows 10 1507 by Microsoft
Windows 10 1607 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
Complete system compromise with SYSTEM/administrator privileges, enabling lateral movement, persistence, and data exfiltration from the host and virtual machines.
Likely Case
Local privilege escalation from standard user to administrator/SYSTEM level on the Hyper-V host, allowing control over virtualization infrastructure.
If Mitigated
Limited impact due to proper access controls, network segmentation, and monitoring preventing successful exploitation.
🎯 Exploit Status
Requires authenticated access to the Hyper-V host. Exploitation likely involves crafting specific inputs to trigger integer overflow.
🛠️ 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-2025-54091
Restart Required: Yes
Instructions:
1. Open Windows Update Settings
2. Check for updates
3. Install all security updates
4. Restart system when prompted
🔧 Temporary Workarounds
Disable Hyper-V
windowsRemove Hyper-V role/feature if not required
Disable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V-All
Restrict Hyper-V Management Access
windowsLimit who can manage Hyper-V to essential administrators only
🧯 If You Can't Patch
- Implement strict access controls to Hyper-V hosts
- Monitor for privilege escalation attempts and Hyper-V service anomalies
🔍 How to Verify
Check if Vulnerable:
Check if Hyper-V is enabled and system has not applied the security patch for CVE-2025-54091Check Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows the relevant security patch installed and Hyper-V service is running📡 Detection & Monitoring
Log Indicators:
- Unusual Hyper-V service activity
- Privilege escalation events in Windows Security logs
- Process creation from Hyper-V components with elevated privileges
Network Indicators:
- Unusual management traffic to Hyper-V hosts
SIEM Query:
EventID=4688 AND (ProcessName LIKE '%vmwp%' OR ProcessName LIKE '%vmms%') AND NewProcessName LIKE '%cmd%' OR NewProcessName LIKE '%powershell%'