CVE-2025-47164
📋 TL;DR
A use-after-free vulnerability in Microsoft Office allows attackers to execute arbitrary code on affected systems by tricking users into opening malicious documents. This affects all users running vulnerable versions of Microsoft Office on Windows systems. Successful exploitation requires user interaction but can lead to full system compromise.
💻 Affected Systems
- Microsoft Office
- Microsoft 365 Apps
- Office LTSC
📦 What is this software?
365 Apps by Microsoft
Office by Microsoft
Office by Microsoft
Office by Microsoft
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
Office Long Term Servicing Channel by Microsoft
View all CVEs affecting Office Long Term Servicing Channel →
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with administrative privileges, data exfiltration, ransomware deployment, and lateral movement across the network.
Likely Case
Local privilege escalation leading to credential theft, data access, and persistence mechanisms installation.
If Mitigated
Limited impact due to application sandboxing, reduced privileges, or blocked malicious document delivery.
🎯 Exploit Status
Exploitation requires social engineering to deliver malicious document. No public exploit code available at advisory publication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Update Catalog for specific KB numbers
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-47164
Restart Required: Yes
Instructions:
1. Open Microsoft Office application
2. Go to File > Account > Update Options
3. Select 'Update Now'
4. Restart Office applications when prompted
5. Alternatively, use Windows Update for system-wide deployment
🔧 Temporary Workarounds
Block Office file types via email filtering
allPrevent delivery of potentially malicious Office documents through email gateways
Enable Protected View for all Office documents
windowsForce Office to open all documents from untrusted sources in Protected View mode
File > Options > Trust Center > Trust Center Settings > Protected View > Check all three options
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized Office document execution
- Deploy endpoint detection and response (EDR) with behavior monitoring for Office process anomalies
🔍 How to Verify
Check if Vulnerable:
Check Office version against patched versions in Microsoft Security Update GuideCheck Version:
In Word/Excel/PowerPoint: File > Account > About [Application]Verify Fix Applied:
Verify Office build number matches or exceeds patched version in advisory📡 Detection & Monitoring
Log Indicators:
- Office application crashes with memory access violations
- Unusual child processes spawned from Office applications
- Office loading unexpected DLLs or COM objects
Network Indicators:
- Office applications making unexpected outbound connections after document opening
- DNS requests for suspicious domains following Office document access
SIEM Query:
source="windows" AND (process_name="winword.exe" OR process_name="excel.exe" OR process_name="powerpnt.exe") AND (event_id="1000" OR event_id="1001") AND message="ACCESS_VIOLATION"