CVE-2023-29344
📋 TL;DR
This vulnerability allows remote code execution through specially crafted Office documents. Attackers can exploit it by tricking users into opening malicious files, potentially gaining control of affected systems. All users running unpatched Microsoft Office versions are affected.
💻 Affected Systems
- Microsoft Office
- Microsoft 365 Apps
📦 What is this software?
365 Apps by Microsoft
Office by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining administrative privileges, data exfiltration, ransomware deployment, and persistent backdoor installation.
Likely Case
Local user account compromise leading to data theft, credential harvesting, and lateral movement within the network.
If Mitigated
Limited impact with proper application whitelisting, macro restrictions, and user training preventing malicious document execution.
🎯 Exploit Status
Exploitation requires user interaction but is technically straightforward once malicious document is opened.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Security updates released May 2023
Vendor Advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-29344
Restart Required: Yes
Instructions:
1. Open Office application. 2. Go to File > Account > Update Options > Update Now. 3. Install available updates. 4. Restart Office applications. For enterprise: Deploy through Microsoft Update or WSUS.
🔧 Temporary Workarounds
Block Office file types via email filtering
allPrevent delivery of potentially malicious Office documents through email
Enable Office Protected View
windowsForce documents from internet to open in Protected View
Set registry key: HKCU\Software\Microsoft\Office\16.0\Word\Security\ProtectedView\DisableInternetFilesInPV = 0
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized Office execution
- Disable Office macro execution and enforce document signing requirements
🔍 How to Verify
Check if Vulnerable:
Check Office version against patched versions in Microsoft advisory. Unpatched versions before May 2023 updates are vulnerable.Check Version:
In Office: File > Account > About [Application]. PowerShell: Get-WmiObject -Class Win32_Product | Where-Object {$_.Name -like '*Office*'} | Select Name, VersionVerify Fix Applied:
Verify Office applications have May 2023 security updates installed via File > Account > About [Application]📡 Detection & Monitoring
Log Indicators:
- Office application crashes with unusual error codes
- Process creation from Office applications (winword.exe, excel.exe) spawning cmd.exe or powershell.exe
- Unusual network connections from Office processes
Network Indicators:
- Office applications making unexpected outbound connections
- DNS requests for suspicious domains from Office processes
SIEM Query:
Process Creation where (ParentImage contains 'winword.exe' OR ParentImage contains 'excel.exe' OR ParentImage contains 'powerpnt.exe') AND (Image contains 'cmd.exe' OR Image contains 'powershell.exe')