CVE-2021-38101
📋 TL;DR
Corel PhotoPaint Standard 2020 contains an out-of-bounds write vulnerability in CDRRip.dll when parsing malicious CPT files. This allows unauthenticated attackers to achieve arbitrary code execution in the context of the current user if they can trick a victim into opening a crafted file. Only users of Corel PhotoPaint Standard 2020 version 22.0.0.474 are affected.
💻 Affected Systems
- Corel PhotoPaint Standard 2020
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via arbitrary code execution with current user privileges, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Malware installation or data exfiltration when users open malicious CPT files from untrusted sources.
If Mitigated
No impact if users avoid opening untrusted CPT files or if the application is patched.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious file) but is straightforward once the file is crafted.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check Corel updates for version >22.0.0.474
Vendor Advisory: https://www.fortinet.com/blog/threat-research/fortinet-security-researcher-discovers-multiple-vulnerabilities-across-multiple-corel-products
Restart Required: Yes
Instructions:
1. Open Corel PhotoPaint. 2. Go to Help > Check for Updates. 3. Install any available updates. 4. Restart the application.
🔧 Temporary Workarounds
Disable CPT file association
windowsPrevent CPT files from automatically opening in Corel PhotoPaint to reduce attack surface.
Control Panel > Default Programs > Associate a file type or protocol with a program > Select .cpt > Change program > Choose another application
User awareness training
allEducate users to avoid opening CPT files from untrusted sources.
🧯 If You Can't Patch
- Restrict user permissions to limit impact of code execution
- Use application whitelisting to block unauthorized executables
🔍 How to Verify
Check if Vulnerable:
Check the application version in Help > About Corel PhotoPaint; if version is 22.0.0.474, it is vulnerable.Check Version:
In Corel PhotoPaint: Help > About Corel PhotoPaintVerify Fix Applied:
Verify the version is updated to a newer release after patching.📡 Detection & Monitoring
Log Indicators:
- Application crashes or unexpected behavior when opening CPT files
- Process creation from Corel PhotoPaint with suspicious command lines
Network Indicators:
- Unusual outbound connections from Corel PhotoPaint process
SIEM Query:
Process creation where parent process contains 'Corel PhotoPaint' and command line contains suspicious patterns🔗 References
- https://www.fortiguard.com/zeroday/FG-VD-21-028
- https://www.fortinet.com/blog/threat-research/fortinet-security-researcher-discovers-multiple-vulnerabilities-across-multiple-corel-products
- https://www.fortiguard.com/zeroday/FG-VD-21-028
- https://www.fortinet.com/blog/threat-research/fortinet-security-researcher-discovers-multiple-vulnerabilities-across-multiple-corel-products
