CVE-2021-31465
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code by exploiting a memory corruption flaw in Foxit Reader's handling of U3D objects in PDF files. Attackers can achieve remote code execution by tricking users into opening malicious PDF files. Users of Foxit Reader 10.1.3.37598 and potentially other versions are affected.
💻 Affected Systems
- Foxit Reader
📦 What is this software?
3d by Foxitsoftware
3d by Foxitsoftware
3d by Foxitsoftware
3d by Foxitsoftware
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining the same privileges as the current user, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Remote code execution in the context of the current user, allowing attackers to install malware, steal sensitive documents, or establish persistence on the system.
If Mitigated
Limited impact if proper application sandboxing, least privilege principles, and network segmentation are implemented, potentially containing the exploit to the application sandbox.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious PDF) but no authentication. The vulnerability is memory corruption-based with known exploitation patterns.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.4 or later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: Yes
Instructions:
1. Download latest Foxit Reader from official website. 2. Run installer. 3. Restart system if prompted. 4. Verify version is 10.1.4 or higher.
🔧 Temporary Workarounds
Disable U3D support
allDisable U3D object rendering in Foxit Reader settings to prevent exploitation
Navigate to Edit > Preferences > 3D & Multimedia > Uncheck 'Enable U3D support'
Use alternative PDF reader
allTemporarily use a different PDF reader that is not vulnerable
🧯 If You Can't Patch
- Implement application whitelisting to block unauthorized PDF readers
- Use network segmentation to isolate systems running vulnerable software
🔍 How to Verify
Check if Vulnerable:
Check Foxit Reader version in Help > About. If version is 10.1.3.37598 or earlier, system is vulnerable.Check Version:
On Windows: wmic product where name="Foxit Reader" get versionVerify Fix Applied:
Verify Foxit Reader version is 10.1.4 or later in Help > About.📡 Detection & Monitoring
Log Indicators:
- Foxit Reader crash logs with memory access violations
- Unexpected process creation from Foxit Reader
Network Indicators:
- Outbound connections from Foxit Reader to unknown IPs
- PDF downloads from untrusted sources
SIEM Query:
process_name:"FoxitReader.exe" AND (event_id:1000 OR event_id:1001) OR process_parent:"FoxitReader.exe"