CVE-2025-54105
📋 TL;DR
A race condition vulnerability in Microsoft Brokering File System allows authenticated attackers to escalate privileges locally. This affects systems running vulnerable versions of Windows where an attacker with initial access can gain higher privileges. Only Windows systems with the vulnerable component are impacted.
💻 Affected Systems
- Microsoft Windows
📦 What is this software?
Windows 11 24h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM/administrator privileges leading to data theft, persistence, and lateral movement.
Likely Case
Local privilege escalation from standard user to administrator/SYSTEM level on compromised systems.
If Mitigated
Limited impact if proper access controls and monitoring are in place to detect privilege escalation attempts.
🎯 Exploit Status
Race conditions require precise timing and may be unstable; requires local authenticated access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Will be specified in Microsoft's monthly security update
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-54105
Restart Required: Yes
Instructions:
1. Check Microsoft Security Update Guide for CVE-2025-54105
2. Apply the latest Windows security update
3. Restart system as required
🔧 Temporary Workarounds
Restrict local user privileges
windowsLimit standard user permissions to reduce impact of privilege escalation
Enable Windows Defender Application Control
windowsRestrict execution of unauthorized binaries to limit post-exploitation
🧯 If You Can't Patch
- Implement strict least privilege access controls for all users
- Monitor for privilege escalation attempts using Windows Event Logs and EDR solutions
🔍 How to Verify
Check if Vulnerable:
Check Windows Update history for applied security patches related to CVE-2025-54105Check Version:
wmic os get caption, version, buildnumberVerify Fix Applied:
Verify the latest Windows security update is installed and system has been restarted📡 Detection & Monitoring
Log Indicators:
- Unexpected process creation with elevated privileges
- Brokering File System access patterns
- Security log Event ID 4688 with elevated token
Network Indicators:
- Not applicable - local exploitation only
SIEM Query:
EventID=4688 AND NewProcessName CONTAINS 'cmd.exe' OR 'powershell.exe' AND SubjectLogonId != TargetLogonId