CVE-2021-38097
📋 TL;DR
CVE-2021-38097 is an out-of-bounds write vulnerability in Corel PDF Fusion 2.6.2.0 that allows arbitrary code execution when parsing malicious PDF files. Users who open crafted PDF files with this software are affected, with exploitation requiring user interaction.
💻 Affected Systems
- Corel PDF Fusion
📦 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 PDF files from untrusted sources.
If Mitigated
Limited impact if users avoid opening untrusted PDFs and software is properly segmented.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious PDF) but no authentication. No public exploit code identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Update to latest version (beyond 2.6.2.0)
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 PDF Fusion. 2. Navigate to Help > Check for Updates. 3. Follow prompts to install latest version. 4. Restart application.
🔧 Temporary Workarounds
Disable PDF Fusion file association
windowsPrevent PDF files from automatically opening with Corel PDF Fusion
Control Panel > Default Programs > Set Default Programs > Choose another program for PDF files
Application control restriction
windowsBlock execution of Corel PDF Fusion via application whitelisting
🧯 If You Can't Patch
- Implement strict email filtering to block malicious PDF attachments
- Educate users to never open PDF files from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Help > About in Corel PDF Fusion for version 2.6.2.0Check Version:
Not applicable - check via application GUIVerify Fix Applied:
Verify version is updated beyond 2.6.2.0 in Help > About📡 Detection & Monitoring
Log Indicators:
- Application crashes of Corel PDF Fusion
- Unusual process creation from PDF Fusion
Network Indicators:
- Outbound connections from PDF Fusion process to unknown IPs
SIEM Query:
Process: "PDFFusion.exe" AND (EventID: 1000 OR ParentProcess: suspicious.exe)🔗 References
- https://www.fortiguard.com/zeroday/FG-VD-21-026
- https://www.fortinet.com/blog/threat-research/fortinet-security-researcher-discovers-multiple-vulnerabilities-across-multiple-corel-products
- https://www.fortiguard.com/zeroday/FG-VD-21-026
- https://www.fortinet.com/blog/threat-research/fortinet-security-researcher-discovers-multiple-vulnerabilities-across-multiple-corel-products
