CVE-2021-38568
📋 TL;DR
This vulnerability in Foxit Reader and PhantomPDF allows memory corruption when converting PDF documents to other formats, potentially enabling remote code execution. Attackers could exploit this by tricking users into opening malicious PDF files. All users of affected Foxit software versions are at risk.
💻 Affected Systems
- Foxit Reader
- Foxit PhantomPDF
📦 What is this software?
Foxit Reader by Foxitsoftware
Phantompdf by Foxitsoftware
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with SYSTEM/administrator privileges leading to complete system compromise, data theft, and lateral movement within networks.
Likely Case
Remote code execution with user-level privileges allowing malware installation, credential theft, and persistence mechanisms.
If Mitigated
Application crash or denial of service if memory corruption doesn't lead to successful code execution.
🎯 Exploit Status
Exploitation requires user interaction to open malicious PDF, but no authentication is needed once the file is accessed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.4 and later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: Yes
Instructions:
1. Download Foxit Reader/PhantomPDF 10.1.4 or later from official Foxit website. 2. Run installer with administrative privileges. 3. Follow installation prompts. 4. Restart system after installation completes.
🔧 Temporary Workarounds
Disable PDF conversion features
windowsRemove or restrict access to document conversion functionality through group policy or application settings
Use alternative PDF software
allTemporarily switch to different PDF reader software until patching is complete
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized executables
- Deploy endpoint detection and response (EDR) solutions with memory protection capabilities
🔍 How to Verify
Check if Vulnerable:
Check Help > About in Foxit software and verify version is below 10.1.4Check Version:
On Windows: wmic product where name like "Foxit%" get versionVerify Fix Applied:
Confirm version is 10.1.4 or higher in Help > About dialog📡 Detection & Monitoring
Log Indicators:
- Application crashes during PDF conversion
- Unusual process spawning from Foxit executables
- Memory access violation events in Windows Event Logs
Network Indicators:
- Unexpected outbound connections from Foxit processes
- DNS requests to suspicious domains following PDF file access
SIEM Query:
process_name:"FoxitReader.exe" AND (event_id:1000 OR event_id:1001) OR process_name:"FoxitReader.exe" AND child_process_count > 3