CVE-2021-39825
📋 TL;DR
This vulnerability in Adobe Photoshop Elements allows attackers to execute arbitrary code on a victim's computer by tricking them into opening a malicious TrueType Font (TTF) file. The exploit runs with the same permissions as the current user, potentially leading to full system compromise. All users of Photoshop Elements 2021 and earlier versions are affected.
💻 Affected Systems
- Adobe Photoshop Elements
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system takeover with attacker gaining the same privileges as the logged-in user, enabling data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Malware installation leading to credential theft, data exfiltration, or system disruption for individual users who open malicious font files.
If Mitigated
Limited impact with proper user training and security controls preventing malicious file execution, though system remains vulnerable to targeted attacks.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file) and knowledge of font parsing vulnerabilities. No public exploits have been confirmed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Photoshop Elements 2021 version 19.1 or later
Vendor Advisory: https://helpx.adobe.com/security/products/photoshop_elements/apsb21-77.html
Restart Required: Yes
Instructions:
1. Open Photoshop Elements. 2. Go to Help > Updates. 3. Follow prompts to install available updates. 4. Restart Photoshop Elements after installation completes.
🔧 Temporary Workarounds
Block TTF file execution
allPrevent Photoshop Elements from opening TTF files by modifying file associations or using application control policies.
User awareness training
allEducate users to only open font files from trusted sources and to be cautious of unexpected font files.
🧯 If You Can't Patch
- Restrict Photoshop Elements usage to trusted users only
- Implement application whitelisting to prevent unauthorized Photoshop Elements execution
🔍 How to Verify
Check if Vulnerable:
Check Photoshop Elements version: Open Photoshop Elements > Help > About Photoshop Elements. If version is 19.0 (20210304.m.156367) or earlier, system is vulnerable.Check Version:
Photoshop Elements does not have a command-line version check. Use Help > About Photoshop Elements in the application.Verify Fix Applied:
Verify version is 19.1 or later in Help > About Photoshop Elements. Check that updates show no available updates in Help > Updates.📡 Detection & Monitoring
Log Indicators:
- Photoshop Elements crash logs with font parsing errors
- Unexpected TTF file access in application logs
- Process creation from Photoshop Elements with suspicious parameters
Network Indicators:
- Outbound connections from Photoshop Elements to suspicious domains
- Font file downloads from untrusted sources
SIEM Query:
process_name:"PhotoshopElements.exe" AND (file_extension:".ttf" OR file_extension:".otf") AND event_type:"file_open"