CVE-2021-40709
📋 TL;DR
A buffer overflow vulnerability in Adobe Photoshop allows arbitrary code execution when parsing malicious SVG files. Attackers can exploit this by tricking users into opening specially crafted files, potentially compromising the victim's system. Affects Photoshop versions 21.2.11 and earlier, and 22.5 and earlier.
💻 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, data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation leading to malware installation, credential theft, or data exfiltration from the affected user's account.
If Mitigated
Limited impact due to user awareness training preventing malicious file opens, or application sandboxing containing the exploit.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). No public exploit code available as of analysis date.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Photoshop 21.2.12 and 22.5.1
Vendor Advisory: https://helpx.adobe.com/security/products/photoshop/apsb21-84.html
Restart Required: Yes
Instructions:
1. Open Adobe Creative Cloud application. 2. Navigate to 'Apps' section. 3. Find Photoshop and click 'Update'. 4. Restart Photoshop after update completes.
🔧 Temporary Workarounds
Disable SVG file association
allPrevent Photoshop from automatically opening SVG files by changing file associations
Windows: Control Panel > Default Programs > Associate a file type or protocol with a program
macOS: Right-click SVG file > Get Info > Open With > Change to different application
🧯 If You Can't Patch
- Implement application whitelisting to prevent execution of unauthorized Photoshop versions
- Deploy email/web filtering to block SVG attachments and downloads
🔍 How to Verify
Check if Vulnerable:
Check Photoshop version in Help > About Photoshop. If version is 21.2.11 or earlier, or 22.5 or earlier, system is vulnerable.Check Version:
Photoshop: Help > About PhotoshopVerify Fix Applied:
Verify Photoshop version is 21.2.12 or higher (for 21.x branch) or 22.5.1 or higher (for 22.x branch).📡 Detection & Monitoring
Log Indicators:
- Photoshop crash logs with SVG parsing errors
- Windows Event Logs showing Photoshop process termination
Network Indicators:
- Unusual outbound connections from Photoshop process after SVG file open
SIEM Query:
process_name:"photoshop.exe" AND (file_extension:".svg" OR file_name:"*.svg")