CVE-2024-38240
📋 TL;DR
This vulnerability allows an authenticated attacker to elevate privileges on Windows systems by exploiting a flaw in the Remote Access Connection Manager service. Attackers could gain SYSTEM-level access, potentially taking full control of affected machines. This affects Windows systems with the vulnerable service enabled.
💻 Affected Systems
- Windows Remote Access Connection Manager
📦 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 establishment.
Likely Case
Local privilege escalation allowing attackers to bypass security controls, install additional tools, and access sensitive system resources.
If Mitigated
Limited impact if proper access controls, network segmentation, and monitoring are in place to detect and contain privilege escalation attempts.
🎯 Exploit Status
Requires authenticated access to the target system. The vulnerability involves improper bounds checking (CWE-125) that could lead to memory corruption and privilege escalation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Apply the latest Windows security updates from Microsoft's July 2024 Patch Tuesday or later
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-38240
Restart Required: Yes
Instructions:
1. Open Windows Update settings. 2. Click 'Check for updates'. 3. Install all available security updates. 4. Restart the system when prompted.
🔧 Temporary Workarounds
Disable Remote Access Connection Manager Service
windowsDisables the vulnerable service if not required for business operations
sc config RasMan start= disabled
sc stop RasMan
Restrict Service Permissions
windowsLimit which users can interact with the service
sc sdset RasMan D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWLOCRRC;;;IU)(A;;CCLCSWLOCRRC;;;SU)
🧯 If You Can't Patch
- Implement strict access controls and limit user privileges to reduce attack surface
- Enable enhanced monitoring and logging for privilege escalation attempts and service manipulation
🔍 How to Verify
Check if Vulnerable:
Check if the system has the July 2024 Windows security updates installed. Systems without these updates are vulnerable.Check Version:
wmic qfe list | findstr KB5039211Verify Fix Applied:
Verify the Windows Update history shows installation of KB5039211 (or later) and that the system has been restarted.📡 Detection & Monitoring
Log Indicators:
- Event ID 4688 with process creation from RasMan service
- Unexpected privilege escalation events
- Service manipulation logs in Windows Event Log
Network Indicators:
- Unusual outbound connections following local privilege escalation
- Lateral movement attempts from previously compromised hosts
SIEM Query:
EventID=4688 AND (NewProcessName LIKE '%RasMan%' OR ParentProcessName LIKE '%RasMan%')