CVE-2021-31472
📋 TL;DR
This vulnerability in Foxit Reader allows remote attackers to execute arbitrary code by tricking users into opening a malicious PDF file containing a specially crafted U3D object. It affects users of Foxit Reader 10.1.1.37576 and earlier versions, requiring user interaction to exploit.
💻 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
Full system compromise via remote code execution in the context of the current user, potentially leading to data theft, malware installation, or lateral movement.
Likely Case
Arbitrary code execution on the local system, enabling attackers to steal sensitive information or deploy ransomware.
If Mitigated
Limited impact if patched or with strict file handling policies; exploitation may fail or be contained.
🎯 Exploit Status
Exploitation requires user to open a malicious file; proof-of-concept code is publicly available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.2 or later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: No
Instructions:
1. Open Foxit Reader. 2. Go to Help > Check for Updates. 3. Follow prompts to install the latest version (10.1.2 or higher). 4. Alternatively, download and install the update manually from the Foxit website.
🔧 Temporary Workarounds
Disable U3D object handling
allPrevent Foxit Reader from processing U3D objects in PDF files to block exploitation.
Not applicable; configure via Foxit Reader settings under File > Preferences > Trust Manager > 3D Multimedia.
Use alternative PDF viewer
allTemporarily switch to a different PDF reader that is not affected by this vulnerability.
🧯 If You Can't Patch
- Restrict user permissions to limit the impact of code execution (e.g., run with least privilege).
- Implement application whitelisting to block unauthorized executables from running.
🔍 How to Verify
Check if Vulnerable:
Check Foxit Reader version: Open Foxit Reader, go to Help > About Foxit Reader. If version is 10.1.1.37576 or earlier, it is vulnerable.Check Version:
On Windows: wmic product where name='Foxit Reader' get versionVerify Fix Applied:
After updating, verify the version is 10.1.2 or later using the same About menu.📡 Detection & Monitoring
Log Indicators:
- Unusual process creation from Foxit Reader (e.g., cmd.exe, powershell.exe)
- Crashes or errors in Foxit Reader logs related to U3D handling.
Network Indicators:
- Outbound connections from Foxit Reader to unknown IPs post-exploit.
SIEM Query:
EventID=4688 AND ParentProcessName='FoxitReader.exe' AND NewProcessName IN ('cmd.exe', 'powershell.exe')