CVE-2021-24089
📋 TL;DR
This vulnerability allows remote code execution through malicious HEVC video files in Microsoft's HEVC Video Extensions. Attackers can exploit this by tricking users into opening specially crafted video files, potentially compromising affected Windows systems.
💻 Affected Systems
- Microsoft HEVC Video Extensions
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining SYSTEM privileges and persistent access to the victim's machine.
Likely Case
Local privilege escalation leading to unauthorized access to sensitive data and system resources.
If Mitigated
Limited impact with proper patch management and user education preventing malicious file execution.
🎯 Exploit Status
Requires user interaction to open malicious video file. No known public exploits as of analysis.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: HEVC Video Extensions version 1.0.32763.0 or later
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-24089
Restart Required: No
Instructions:
1. Open Microsoft Store 2. Search for 'HEVC Video Extensions' 3. Click 'Update' if available 4. Alternatively, uninstall and reinstall to get latest version
🔧 Temporary Workarounds
Uninstall HEVC Video Extensions
windowsRemove the vulnerable component entirely
Get-AppxPackage *HEVCVideoExtension* | Remove-AppxPackage
Disable automatic codec processing
windowsPrevent automatic processing of HEVC video files
🧯 If You Can't Patch
- Implement application whitelisting to block execution of HEVC Video Extensions
- Educate users about risks of opening untrusted video files and implement email filtering for video attachments
🔍 How to Verify
Check if Vulnerable:
Check HEVC Video Extensions version in Microsoft Store or via PowerShell: Get-AppxPackage *HEVCVideoExtension* | Select VersionCheck Version:
Get-AppxPackage *HEVCVideoExtension* | Select Name, VersionVerify Fix Applied:
Confirm version is 1.0.32763.0 or higher using same command📡 Detection & Monitoring
Log Indicators:
- Application crashes of HEVCVideoExtension.exe
- Unusual process creation from video player applications
Network Indicators:
- Downloads of HEVC video files from untrusted sources
SIEM Query:
EventID=1000 AND Source='Application Error' AND ProcessName='HEVCVideoExtension.exe'