CVE-2020-10904
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code by exploiting a memory corruption flaw in Foxit PhantomPDF's handling of U3D objects in PDF files. Attackers can craft malicious PDFs that trigger out-of-bounds writes when opened by users. Affected users are those running vulnerable versions of Foxit PhantomPDF who open untrusted PDF files.
💻 Affected Systems
- Foxit PhantomPDF
📦 What is this software?
Phantompdf by Foxitsoftware
Reader by Foxitsoftware
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through remote code execution with the same privileges as the current user, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Malicious actors deliver weaponized PDFs via phishing campaigns, leading to compromise of individual workstations and potential credential harvesting.
If Mitigated
With proper controls like application whitelisting and least privilege, impact is limited to the application crashing or denial of service.
🎯 Exploit Status
Exploitation requires user interaction but no authentication. The vulnerability was disclosed through ZDI with advisory ZDI-20-532, suggesting potential for weaponization.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.7.2 or later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: Yes
Instructions:
1. Download the latest version from Foxit's official website. 2. Run the installer. 3. Follow installation prompts. 4. Restart the system if required by the installer.
🔧 Temporary Workarounds
Disable U3D object rendering
windowsConfigure Foxit PhantomPDF to disable U3D object processing in PDF files
Navigate to Edit > Preferences > Security (Enhanced) > Disable U3D support
Use alternative PDF viewer
allTemporarily use a different PDF viewer that is not vulnerable
🧯 If You Can't Patch
- Implement application control/whitelisting to prevent execution of Foxit PhantomPDF
- Configure email/web gateways to block PDF attachments and downloads from untrusted sources
🔍 How to Verify
Check if Vulnerable:
Check Foxit PhantomPDF version via Help > About. If version is 9.7.1.29511 or earlier, the system is vulnerable.Check Version:
In Foxit PhantomPDF: Help > AboutVerify Fix Applied:
Verify version is 9.7.2 or later via Help > About. Test opening known safe PDFs with U3D content to ensure functionality.📡 Detection & Monitoring
Log Indicators:
- Application crashes of Foxit PhantomPDF
- Unusual process creation from Foxit PhantomPDF
Network Indicators:
- Downloads of PDF files from suspicious sources
- Outbound connections from Foxit PhantomPDF to unknown IPs
SIEM Query:
source="windows" AND (process_name="FoxitPhantomPDF.exe" AND (event_id=1000 OR event_id=1001))