CVE-2021-28549
📋 TL;DR
This CVE describes a buffer overflow vulnerability in Adobe Photoshop that allows arbitrary code execution when parsing malicious JSX files. Attackers can exploit this by tricking users into opening specially crafted files, potentially gaining control of the affected system. Users of Adobe Photoshop versions 21.2.6 and earlier or 22.3 and earlier are affected.
💻 Affected Systems
- Adobe Photoshop
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the victim's computer, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation leading to data exfiltration, installation of persistent malware, or credential harvesting from the compromised user account.
If Mitigated
Limited impact with proper application sandboxing, user awareness training preventing malicious file execution, and network segmentation containing any potential breach.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file) but no authentication. The buffer overflow mechanism is well-understood, making exploitation feasible for skilled attackers.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Photoshop 21.2.7 and 22.4
Vendor Advisory: https://helpx.adobe.com/security/products/photoshop/apsb21-28.html
Restart Required: Yes
Instructions:
1. Open Adobe Creative Cloud application. 2. Navigate to the 'Apps' section. 3. Find Adobe Photoshop and click 'Update'. 4. Follow the installation prompts. 5. Restart Photoshop after update completes.
🔧 Temporary Workarounds
Disable JSX file association
allRemove file association for .jsx files to prevent automatic opening in Photoshop
Windows: assoc .jsx=
Windows: ftype JSXFile=
macOS: Remove .jsx from Photoshop's 'Open With' defaults in Finder
Application control blocking
allUse application whitelisting to prevent execution of Photoshop with untrusted files
Windows: Configure AppLocker or Windows Defender Application Control rules
macOS: Configure Gatekeeper or third-party application control solutions
🧯 If You Can't Patch
- Implement strict email filtering to block JSX attachments
- Deploy endpoint detection and response (EDR) solutions to monitor for suspicious Photoshop behavior
🔍 How to Verify
Check if Vulnerable:
Check Photoshop version in Help > About Photoshop. If version is 21.2.6 or earlier, or 22.3 or earlier, the system is vulnerable.Check Version:
Photoshop: Help > About PhotoshopVerify Fix Applied:
Verify Photoshop version is 21.2.7 or higher for version 21.x, or 22.4 or higher for version 22.x.📡 Detection & Monitoring
Log Indicators:
- Photoshop crash logs showing buffer overflow errors
- Windows Event Logs showing Photoshop process termination with exception codes
- Application logs showing unexpected file parsing
Network Indicators:
- Outbound connections from Photoshop process to unexpected destinations
- DNS queries for command and control domains following Photoshop execution
SIEM Query:
process_name:"photoshop.exe" AND (event_id:1000 OR exception_code:* OR file_extension:".jsx")