CVE-2024-26170
📋 TL;DR
This vulnerability in Windows Composite Image File System (CimFS) allows attackers to gain elevated privileges on affected systems. It affects Windows systems with CimFS enabled, potentially allowing local attackers to execute code with SYSTEM privileges.
💻 Affected Systems
- Windows Composite Image File System (CimFS)
📦 What is this software?
Windows 10 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 21h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain SYSTEM privileges, enabling complete system compromise, data theft, persistence establishment, and lateral movement across the network.
Likely Case
Local attackers escalate privileges from standard user to SYSTEM, enabling installation of malware, credential harvesting, and bypassing security controls.
If Mitigated
With proper access controls and monitoring, impact is limited to isolated systems with rapid detection and containment.
🎯 Exploit Status
Requires local access and user-level privileges to exploit. No public exploit code available at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: March 2024 security updates (KB5035853 for Windows 11, KB5035849 for Windows 10, etc.)
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-26170
Restart Required: Yes
Instructions:
1. Apply March 2024 Windows security updates via Windows Update. 2. For enterprise environments, deploy updates through WSUS or SCCM. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Disable CimFS if not required
windowsDisable the Composite Image File System feature if not needed for your environment
Disable-WindowsOptionalFeature -FeatureName CimFS -Online
🧯 If You Can't Patch
- Implement strict access controls and least privilege principles to limit local user access
- Enable enhanced monitoring for privilege escalation attempts and suspicious process creation
🔍 How to Verify
Check if Vulnerable:
Check if March 2024 security updates are installed via 'systeminfo' command or Windows Update historyCheck Version:
wmic qfe list | findstr KB5035853 (or appropriate KB number for your OS)Verify Fix Applied:
Verify KB5035853 (Windows 11) or KB5035849 (Windows 10) is installed in Windows Update history📡 Detection & Monitoring
Log Indicators:
- Event ID 4688: New process creation with elevated privileges
- Event ID 4672: Special privileges assigned to new logon
- Unexpected SYSTEM privilege processes from user accounts
Network Indicators:
- Lateral movement attempts following local privilege escalation
- Unusual outbound connections from previously low-privilege accounts
SIEM Query:
EventID=4688 AND NewProcessName="*" AND SubjectUserName!="SYSTEM" AND TokenElevationType="%%1938"