CVE-2024-38191
📋 TL;DR
This CVE describes an elevation of privilege vulnerability in the Windows Kernel Streaming Service Driver. It allows authenticated attackers to execute arbitrary code with SYSTEM privileges, affecting Windows systems with the vulnerable driver installed. Attackers must already have local access to exploit this vulnerability.
💻 Affected Systems
- Windows
📦 What is this software?
Windows 10 1607 by Microsoft
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 authenticated attacker gains full SYSTEM privileges, enabling complete system compromise, data theft, persistence establishment, and lateral movement across the network.
Likely Case
Malicious insiders or attackers with initial access escalate privileges to bypass security controls, install malware, or access sensitive system resources.
If Mitigated
With proper access controls and monitoring, exploitation attempts can be detected and contained before significant damage occurs.
🎯 Exploit Status
Exploitation requires local authenticated access. The vulnerability is in a kernel driver, making exploitation relatively straightforward for attackers with the right knowledge.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: July 2024 security updates (KB5040442 for Windows 10, KB5040437 for Windows 11, etc.)
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-38191
Restart Required: Yes
Instructions:
1. Apply the July 2024 Windows security updates via Windows Update. 2. For enterprise environments, deploy updates through WSUS, SCCM, or Intune. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Disable Kernel Streaming Service Driver
windowsDisable the vulnerable driver if not required for system functionality
sc config ks.sys start= disabled
sc stop ks.sys
Restrict driver loading
windowsUse Windows Defender Application Control to restrict loading of vulnerable drivers
🧯 If You Can't Patch
- Implement strict access controls to limit who can authenticate to vulnerable systems
- Enable Windows Defender Exploit Guard and configure Attack Surface Reduction rules
🔍 How to Verify
Check if Vulnerable:
Check if the system has the vulnerable driver version by examining driver files or checking Windows Update history for missing July 2024 patchesCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify the July 2024 security updates are installed via 'winver' command or Windows Update history📡 Detection & Monitoring
Log Indicators:
- Event ID 4697: Service installation in Security logs
- Suspicious driver loading events
- Privilege escalation attempts in Windows Security logs
Network Indicators:
- Unusual outbound connections from systems after local authentication events
- Lateral movement attempts from previously compromised systems
SIEM Query:
EventID=4697 AND (ServiceFileName="*ks.sys*" OR ServiceName="Kernel Streaming Service")