CVE-2024-38238
📋 TL;DR
This is a Windows kernel driver vulnerability in the Kernel Streaming Service that allows local attackers to escalate privileges from a low-privileged account to SYSTEM level. It affects Windows systems where an attacker already has some initial access. The vulnerability stems from a heap-based buffer overflow in the driver.
💻 Affected Systems
- Windows
📦 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 21h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 10 22h2 by Microsoft
Windows 11 21h2 by Microsoft
Windows 11 22h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 23h2 by Microsoft
Windows 11 24h2 by Microsoft
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM privileges, enabling installation of malware, data theft, lateral movement, and persistence mechanisms.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install backdoors, or access sensitive system resources.
If Mitigated
Limited impact if proper endpoint protection, least privilege principles, and network segmentation are in place.
🎯 Exploit Status
Requires local access and ability to execute code. Exploitation involves triggering a heap-based buffer overflow in kernel space.
🛠️ 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-2024-38238
Restart Required: Yes
Instructions:
1. Apply July 2024 Windows security updates via Windows Update. 2. For enterprise environments, deploy through WSUS or Microsoft Endpoint Configuration Manager. 3. Restart systems after patch installation.
🔧 Temporary Workarounds
Disable Kernel Streaming Service
windowsDisables the vulnerable driver service to prevent exploitation
sc config ks start= disabled
sc stop ks
Apply Windows Defender Exploit Protection
windowsConfigure Exploit Protection to mitigate heap corruption attacks
🧯 If You Can't Patch
- Implement strict least privilege principles to limit initial access
- Deploy endpoint detection and response (EDR) solutions to detect privilege escalation attempts
🔍 How to Verify
Check if Vulnerable:
Check if ks.sys driver version is older than the patched version (10.0.22621.3880 for Windows 11 22H2). Use: Get-ItemProperty -Path 'C:\Windows\System32\drivers\ks.sys' | Select-Object VersionInfoCheck Version:
wmic os get Caption, Version, BuildNumberVerify Fix Applied:
Verify Windows Update history for July 2024 security updates or check ks.sys driver version matches patched version.📡 Detection & Monitoring
Log Indicators:
- Event ID 4688 with ks.sys in process path
- Unexpected kernel driver loads
- Privilege escalation attempts in security logs
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
EventID=4688 AND ProcessName LIKE '%ks.sys%' OR EventID=4104 AND ScriptBlockText LIKE '%ks%'