CVE-2020-1477
📋 TL;DR
CVE-2020-1477 is a memory corruption vulnerability in Windows Media Foundation that allows attackers to execute arbitrary code with user privileges. It affects Windows systems and can be exploited through malicious documents or webpages. Users who open untrusted files or browse untrusted websites are at risk.
💻 Affected Systems
- Windows Media Foundation
📦 What is this software?
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 10 by Microsoft
Windows 7 by Microsoft
Windows 8.1 by Microsoft
Windows Rt 8.1 by Microsoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining administrative privileges, installing malware, stealing data, and creating persistent backdoors.
Likely Case
Attacker gains user-level access to execute code, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
If Mitigated
Limited impact with proper patching and security controls; exploitation attempts blocked by security software.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file or visiting malicious site). No public exploit code was available at disclosure.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: August 2020 security updates (KB4565351 for Windows 10 2004, etc.)
Vendor Advisory: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-1477
Restart Required: Yes
Instructions:
1. Apply August 2020 Windows security updates via Windows Update. 2. For enterprise: Deploy through WSUS or SCCM. 3. Verify update installation with systeminfo command.
🔧 Temporary Workarounds
Disable Windows Media Foundation
windowsDisables the vulnerable component but may break media functionality
dism /online /disable-feature /featurename:WindowsMediaPlayer
dism /online /disable-feature /featurename:MediaPlayback
Application Control Policies
windowsRestrict execution of untrusted media files via AppLocker or Windows Defender Application Control
🧯 If You Can't Patch
- Implement application whitelisting to block execution of untrusted media files
- Use network segmentation to isolate vulnerable systems and restrict internet access
🔍 How to Verify
Check if Vulnerable:
Check Windows version and if August 2020 security updates are installed via systeminfo or Get-Hotfix in PowerShellCheck Version:
systeminfo | findstr /B /C:"OS Name" /C:"OS Version"Verify Fix Applied:
Verify KB4565351 (or relevant August 2020 update) is installed using: wmic qfe list | findstr KB4565351📡 Detection & Monitoring
Log Indicators:
- Windows Event Logs: Application crashes in wmplayer.exe or related media processes
- Security logs: Unexpected process creation from media files
Network Indicators:
- Unusual outbound connections from media applications
- Downloads of suspicious media files
SIEM Query:
EventID=1000 OR EventID=1001 AND SourceName='Application Error' AND ProcessName LIKE '%wmplayer%' OR '%mf%'