CVE-2025-53784
📋 TL;DR
A use-after-free vulnerability in Microsoft Office Word 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 Word. Successful exploitation gives attackers the same privileges as the logged-in user.
💻 Affected Systems
- Microsoft Office Word
- Microsoft 365 Apps
- Microsoft Office LTSC
📦 What is this software?
365 Apps by Microsoft
365 Apps 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
Full system compromise with attacker gaining complete control over the victim's computer, enabling data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation leading to data exfiltration, credential theft, or installation of persistent malware on the affected system.
If Mitigated
Limited impact with proper application sandboxing and user privilege restrictions, potentially resulting in application crash rather than code execution.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious document). No public exploit code is currently available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: May 2025 Security Update for Microsoft Office
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-53784
Restart Required: Yes
Instructions:
1. Open any Office application. 2. Go to File > Account > Update Options > Update Now. 3. Restart the computer after update completes. For enterprise deployments, deploy through Microsoft Endpoint Configuration Manager or WSUS.
🔧 Temporary Workarounds
Block Office macros from the internet
windowsPrevents execution of macros in documents from internet sources
Set-ItemProperty -Path "HKLM:\SOFTWARE\Policies\Microsoft\Office\16.0\Word\Security" -Name "BlockContentExecutionFromInternet" -Value 1 -Type DWord
Enable Protected View for all files
windowsForces all documents to open in Protected View by default
Set-ItemProperty -Path "HKCU:\Software\Microsoft\Office\16.0\Word\Security\ProtectedView" -Name "DisableInternetFilesInPV" -Value 0 -Type DWord
🧯 If You Can't Patch
- Implement application allowlisting to restrict which users can run Microsoft Word
- Deploy email filtering to block .doc and .docx attachments from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Word version via File > Account > About Word. If version is earlier than the May 2025 update, system is vulnerable.Check Version:
powershell "Get-ItemProperty 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*' | Where-Object {$_.DisplayName -like '*Word*'} | Select-Object DisplayName, DisplayVersion"Verify Fix Applied:
Verify Word version shows the May 2025 update in About Word, or check Windows Update history for KB5000000+ updates.📡 Detection & Monitoring
Log Indicators:
- Windows Event ID 1000 for Word crashes
- Office telemetry logs showing document parsing errors
- Antivirus alerts for malicious Office documents
Network Indicators:
- Unusual outbound connections from Word.exe process
- SMB or HTTP traffic to suspicious IPs after document opening
SIEM Query:
source="*windows*" event_id=1000 process_name="WINWORD.EXE" | stats count by host