CVE-2020-10899
📋 TL;DR
This vulnerability in Foxit Reader allows remote attackers to execute arbitrary code by tricking users into opening malicious PDF files containing specially crafted XFA templates. The flaw exists due to improper validation of object existence before operations, leading to use-after-free conditions. Users of affected Foxit Reader versions are at risk.
💻 Affected Systems
- Foxit Reader
📦 What is this software?
Phantompdf by Foxitsoftware
Reader 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
Malware installation on individual workstations through phishing emails with malicious PDF attachments, resulting in data exfiltration or credential theft.
If Mitigated
Limited impact with proper application sandboxing, endpoint protection, and user training preventing successful exploitation attempts.
🎯 Exploit Status
User interaction required (opening malicious file). Exploit details were published by ZDI and likely incorporated into exploit kits.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Foxit Reader 9.7.2 or later
Vendor Advisory: https://www.foxitsoftware.com/support/security-bulletins.php
Restart Required: No
Instructions:
1. Download latest Foxit Reader from official website. 2. Run installer. 3. Follow installation prompts. 4. Verify version is 9.7.2 or higher.
🔧 Temporary Workarounds
Disable JavaScript in Foxit Reader
allPrevents execution of malicious JavaScript that could trigger the vulnerability
Open Foxit Reader > File > Preferences > JavaScript > Uncheck 'Enable JavaScript'
Use Protected View
allOpen PDFs in sandboxed mode to limit potential damage
Open Foxit Reader > File > Preferences > General > Check 'Open cross-domain PDFs in Protected View'
🧯 If You Can't Patch
- Block PDF files from untrusted sources at email gateways and web proxies
- Implement application whitelisting to prevent unauthorized executables from running
🔍 How to Verify
Check if Vulnerable:
Check Foxit Reader version in Help > About. If version is 9.7.1.29511 or earlier, system is vulnerable.Check Version:
On Windows: wmic product where name="Foxit Reader" get versionVerify Fix Applied:
Verify version is 9.7.2 or higher in Help > About. Test with known safe PDF files to ensure functionality.📡 Detection & Monitoring
Log Indicators:
- Application crashes in Foxit Reader logs
- Unusual process creation from Foxit Reader
- Failed PDF file parsing attempts
Network Indicators:
- Outbound connections from Foxit Reader to unknown IPs
- DNS requests for suspicious domains after PDF opening
SIEM Query:
process_name:"FoxitReader.exe" AND (event_id:1000 OR event_id:1001) OR process_parent_name:"FoxitReader.exe" AND process_name NOT IN (allowed_process_list)