CVE-2024-26237
📋 TL;DR
This vulnerability allows an authenticated attacker to bypass Windows Defender Credential Guard protections and gain elevated privileges on affected Windows systems. Attackers could potentially access sensitive credential information stored in memory. This affects Windows systems with Credential Guard enabled.
💻 Affected Systems
- Windows Defender Credential Guard
📦 What is this software?
Windows 10 1809 by Microsoft
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
An attacker gains SYSTEM-level privileges, accesses all protected credentials including domain admin credentials, and moves laterally across the network with elevated access.
Likely Case
Local authenticated attacker elevates privileges to access protected credentials for lateral movement within the environment.
If Mitigated
With proper patch management and Credential Guard configuration, impact is limited to local privilege escalation on already compromised systems.
🎯 Exploit Status
Requires local authenticated access. Exploitation involves bypassing memory protection mechanisms in Credential Guard.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: April 2024 security updates (KB5036893 for Windows 11, KB5036892 for Windows 10, etc.)
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-26237
Restart Required: Yes
Instructions:
1. Apply April 2024 Windows security updates via Windows Update. 2. For enterprise environments, deploy updates through WSUS or Microsoft Endpoint Configuration Manager. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Disable Credential Guard
windowsTemporarily disable Credential Guard to mitigate the vulnerability (not recommended for production as it removes credential protection)
Disable via Group Policy: Computer Configuration > Administrative Templates > System > Device Guard > Turn On Virtualization Based Security > Disabled
🧯 If You Can't Patch
- Restrict local administrator privileges to minimize attack surface
- Implement application control policies to prevent unauthorized code execution
🔍 How to Verify
Check if Vulnerable:
Check if Credential Guard is enabled: Run 'msinfo32' and check 'Virtualization-based security' status. If 'Credential Guard' shows as 'Running', system is vulnerable if unpatched.Check Version:
wmic os get caption, version, buildnumber, csdversionVerify Fix Applied:
Verify April 2024 security updates are installed via 'winver' command or Windows Update history. Confirm Credential Guard is still enabled and functioning.📡 Detection & Monitoring
Log Indicators:
- Event ID 4688 with suspicious parent processes attempting to access lsass.exe
- Credential Guard related errors in System logs
- Unexpected privilege escalation events
Network Indicators:
- Unusual authentication attempts from previously compromised systems
- Lateral movement using stolen credentials
SIEM Query:
EventID=4688 AND (ProcessName="*lsass*" OR ParentProcessName contains suspicious terms) AND NewProcessName contains privilege escalation tools