CVE-2025-29816
📋 TL;DR
This vulnerability allows attackers to bypass security features in Microsoft Word through improper input validation. Attackers can exploit this over a network to potentially execute malicious code or access restricted content. All users running vulnerable versions of Microsoft Word are affected.
💻 Affected Systems
- Microsoft Office Word
📦 What is this software?
365 Apps 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 →
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 →
Word by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution leading to complete system compromise, data theft, or ransomware deployment.
Likely Case
Security feature bypass allowing unauthorized document access or limited code execution within Word's context.
If Mitigated
Attack blocked by network segmentation, application control policies, or macro restrictions.
🎯 Exploit Status
Network-based exploitation suggests relatively straightforward attack vectors once details are known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific version
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-29816
Restart Required: Yes
Instructions:
1. Open Microsoft Word. 2. Go to File > Account > Update Options > Update Now. 3. Restart Word after update completes. 4. Alternatively, use Windows Update for system-wide Office updates.
🔧 Temporary Workarounds
Block Office macros from untrusted sources
windowsConfigure Group Policy to block macros from untrusted locations
gpedit.msc > User Configuration > Administrative Templates > Microsoft Word 2016 > Word Options > Security > Trust Center > Block macros from running in Office files from the Internet
Use Protected View for untrusted documents
windowsForce all documents from untrusted sources to open in Protected View
File > Options > Trust Center > Trust Center Settings > Protected View > Enable all Protected View options
🧯 If You Can't Patch
- Implement application control to restrict Word execution to trusted locations only
- Use network segmentation to isolate Word traffic and block external document sources
🔍 How to Verify
Check if Vulnerable:
Check Word version via File > Account > About Word and compare with Microsoft's patched version listCheck Version:
winword.exe /?Verify Fix Applied:
Verify Word version matches or exceeds patched version in Microsoft advisory📡 Detection & Monitoring
Log Indicators:
- Unusual Word process spawning child processes
- Multiple failed document parsing attempts
- Security feature bypass events in Office logs
Network Indicators:
- Unexpected network connections from Word process
- Downloads of suspicious document files followed by Word execution
SIEM Query:
source="*office*" AND (event_id=1 OR process_name="winword.exe") AND (parent_process!="explorer.exe" OR command_line="*http*")