CVE-2021-40757
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code on systems running vulnerable versions of Adobe After Effects by tricking users into opening malicious MXF files. The vulnerability affects After Effects 18.4.1 and earlier versions, putting users who process untrusted media files at risk of complete system compromise.
💻 Affected Systems
- Adobe After Effects
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with attacker gaining the same privileges as the current user, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation leading to malware installation, data exfiltration, or persistence mechanisms being established on the compromised system.
If Mitigated
Limited impact due to user awareness training, application sandboxing, and restricted file handling policies preventing malicious file execution.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file) and knowledge of memory corruption techniques.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 18.4.2 and later
Vendor Advisory: https://helpx.adobe.com/security/products/after_effects/apsb21-79.html
Restart Required: Yes
Instructions:
1. Open Adobe Creative Cloud application. 2. Navigate to 'Apps' tab. 3. Find Adobe After Effects. 4. Click 'Update' button. 5. Restart computer after installation completes.
🔧 Temporary Workarounds
Restrict MXF file handling
allBlock or restrict processing of MXF files from untrusted sources
Application sandboxing
allRun After Effects in restricted environment to limit potential damage
🧯 If You Can't Patch
- Implement strict user awareness training about opening files from untrusted sources
- Deploy application control policies to restrict After Effects execution to trusted users only
🔍 How to Verify
Check if Vulnerable:
Check After Effects version in Help > About After Effects menuCheck Version:
Not applicable - check via application GUIVerify Fix Applied:
Verify version is 18.4.2 or higher in Help > About After Effects menu📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing MXF files
- Unusual process spawning from After Effects
Network Indicators:
- Unexpected outbound connections from After Effects process
SIEM Query:
Process:After Effects AND (Event:Crash OR Parent:After Effects AND Process:cmd.exe)