CVE-2025-49696
📋 TL;DR
This vulnerability allows an attacker to read memory outside the intended buffer in Microsoft Office applications, potentially leading to local code execution. Users who open malicious Office documents (Word, Excel, PowerPoint) from untrusted sources are affected. The attacker must convince the victim to open a specially crafted file.
💻 Affected Systems
- Microsoft Office
- Microsoft Word
- Microsoft Excel
- Microsoft PowerPoint
📦 What is this software?
365 Apps by Microsoft
365 Apps by Microsoft
Office by Microsoft
Office 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 →
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 compromise with attacker gaining full control of the victim's computer, data theft, and lateral movement within the network.
Likely Case
Local privilege escalation leading to data exfiltration, installation of malware, or persistence mechanisms on the compromised system.
If Mitigated
Limited impact with proper application sandboxing, memory protection mechanisms, and user awareness preventing malicious file execution.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious document). No public exploit code available at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Microsoft Security Update Guide for specific patch versions
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-49696
Restart Required: Yes
Instructions:
1. Open any Office application
2. Go to File > Account > Update Options
3. Select 'Update Now'
4. Restart computer after update completes
5. Alternatively, use Windows Update for system-wide Office updates
🔧 Temporary Workarounds
Disable Office macro execution
windowsPrevents execution of potentially malicious macros in Office documents
Set registry key: HKEY_CURRENT_USER\Software\Microsoft\Office\16.0\Word\Security\VBAWarnings = 2
Or use Group Policy: Computer Configuration > Administrative Templates > Microsoft Office 2016 > Security Settings > Trust Center > Macro Settings
Use Protected View
windowsOpen untrusted documents in read-only Protected View mode
Ensure Protected View is enabled in Trust Center settings
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized Office document execution
- Deploy email filtering to block Office documents from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Office version against patched versions in Microsoft Security Update GuideCheck Version:
In Office application: File > Account > About [Application Name]Verify Fix Applied:
Verify Office version matches or exceeds patched version listed in Microsoft advisory📡 Detection & Monitoring
Log Indicators:
- Office application crashes with memory access violations
- Unusual process creation from Office applications
- Multiple failed document parsing attempts
Network Indicators:
- Outbound connections from Office processes to unknown IPs
- DNS requests for suspicious domains from Office processes
SIEM Query:
source="windows" AND (event_id=1000 OR event_id=1001) AND process_name="WINWORD.EXE" OR process_name="EXCEL.EXE" OR process_name="POWERPNT.EXE" AND exception_code="0xc0000005"