CVE-2025-55691
📋 TL;DR
CVE-2025-55691 is a use-after-free vulnerability in Windows PrintWorkflowUserSvc that allows authenticated attackers to execute arbitrary code with elevated privileges. This affects Windows systems where the print workflow service is enabled. Attackers need local access to exploit this vulnerability.
💻 Affected Systems
- Windows PrintWorkflowUserSvc
📦 What is this software?
Windows 11 24h2 by Microsoft
Windows 11 25h2 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with SYSTEM privileges, enabling installation of persistent malware, credential theft, and lateral movement across the network.
Likely Case
Local privilege escalation from standard user to SYSTEM or administrator privileges, allowing attackers to bypass security controls and install additional payloads.
If Mitigated
Limited impact with proper privilege separation and application control policies in place, potentially preventing successful exploitation.
🎯 Exploit Status
Requires local authenticated access and knowledge of memory corruption techniques. Use-after-free vulnerabilities typically require precise timing and memory manipulation.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55691
Restart Required: Yes
Instructions:
1. Open Windows Update settings
2. Check for updates
3. Install all available security updates
4. Restart the system when prompted
🔧 Temporary Workarounds
Disable PrintWorkflowUserSvc
windowsDisables the vulnerable service to prevent exploitation
sc config PrintWorkflowUserSvc start= disabled
sc stop PrintWorkflowUserSvc
Restrict service permissions
windowsApply stricter ACLs to the PrintWorkflowUserSvc to limit attack surface
sc sdset PrintWorkflowUserSvc D:(A;;CCLCSWRPWPDTLOCRRC;;;SY)(A;;CCDCLCSWRPWPDTLOCRSDRCWDWO;;;BA)(A;;CCLCSWLOCRRC;;;IU)(A;;CCLCSWLOCRRC;;;SU)
🧯 If You Can't Patch
- Implement application control policies to prevent unauthorized code execution
- Enforce principle of least privilege and restrict standard user permissions
🔍 How to Verify
Check if Vulnerable:
Check if PrintWorkflowUserSvc is running and verify Windows version against affected versions in Microsoft advisoryCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify Windows Update history shows the relevant security patch installed and PrintWorkflowUserSvc is either patched or disabled📡 Detection & Monitoring
Log Indicators:
- Event ID 7036 for PrintWorkflowUserSvc service stops/starts
- Unexpected process creation with SYSTEM privileges
- Memory access violations in application logs
Network Indicators:
- Unusual outbound connections from systems with print services
SIEM Query:
EventID=7036 AND ServiceName="PrintWorkflowUserSvc" | stats count by _time, Computer