CVE-2021-27271
📋 TL;DR
This vulnerability in Foxit PhantomPDF allows remote attackers to execute arbitrary code by tricking users into opening malicious PDF files containing specially crafted U3D objects. The flaw is an out-of-bounds read condition due to improper validation of user-supplied data. Users of affected Foxit PhantomPDF versions are at risk.
💻 Affected Systems
- Foxit PhantomPDF
📦 What is this software?
Foxit Reader by Foxitsoftware
Phantompdf by Foxitsoftware
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise via remote code execution with current user privileges, potentially leading to data theft, ransomware deployment, or lateral movement.
Likely Case
Malicious actors deliver weaponized PDFs via phishing campaigns to execute malware or steal credentials from the compromised system.
If Mitigated
Limited impact with proper security controls like application whitelisting, network segmentation, and user awareness training preventing successful exploitation.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file) but is technically straightforward once the malicious PDF is delivered.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.1.1 or later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: Yes
Instructions:
1. Download latest version from Foxit website. 2. Run installer. 3. Restart system. 4. Verify update in Help > About.
🔧 Temporary Workarounds
Disable U3D object processing
windowsConfigure Foxit PhantomPDF to disable or restrict processing of U3D objects 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 affected by this vulnerability.
🧯 If You Can't Patch
- Implement application whitelisting to block execution of unauthorized binaries.
- Deploy network segmentation to limit lateral movement from compromised systems.
🔍 How to Verify
Check if Vulnerable:
Check Foxit PhantomPDF version in Help > About menu. If version is 10.1.0.37527 or earlier, system is vulnerable.Check Version:
In Foxit PhantomPDF: Help > AboutVerify Fix Applied:
Verify version is 10.1.1 or later in Help > About menu after patching.📡 Detection & Monitoring
Log Indicators:
- Application crashes in Foxit PhantomPDF logs
- Unusual process creation from Foxit processes
- Security software alerts for PDF file execution
Network Indicators:
- Outbound connections from Foxit processes to unknown IPs
- DNS requests for suspicious domains following PDF opening
SIEM Query:
source="foxit_logs" AND (event_type="crash" OR process_name="phantompdf.exe")