CVE-2020-8850
📋 TL;DR
CVE-2020-8850 is a remote code execution vulnerability in Foxit Reader that allows attackers to execute arbitrary code by tricking users into opening malicious JPEG2000 files. The vulnerability exists due to improper validation of JPEG2000 data, leading to a heap-based buffer overflow. Users of Foxit Reader 9.7.0.29455 and earlier versions are affected.
💻 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 full control of the victim's computer, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Malware installation leading to data exfiltration, credential theft, or system disruption for individual users who open malicious files.
If Mitigated
Limited impact with proper security controls like application sandboxing, network segmentation, and user awareness training preventing successful exploitation.
🎯 Exploit Status
Exploitation requires user interaction (opening malicious file). The vulnerability was discovered by Zero Day Initiative (ZDI-CAN-9415) and has public proof-of-concept code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 9.7.1.29511 and 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 computer. 4. Verify version is 9.7.1.29511 or higher.
🔧 Temporary Workarounds
Disable JPEG2000 file association
windowsPrevent Foxit Reader from automatically opening JPEG2000 files
Control Panel > Default Programs > Associate a file type or protocol with a program > Change .jp2/.j2k/.jpx/.jpf extensions to open with another application
Use alternative PDF reader
allTemporarily switch to a different PDF reader until patched
🧯 If You Can't Patch
- Implement application whitelisting to prevent unauthorized executables
- Deploy network segmentation to limit lateral movement if compromised
🔍 How to Verify
Check if Vulnerable:
Check Foxit Reader version in Help > About Foxit ReaderCheck Version:
On Windows: wmic product where name="Foxit Reader" get versionVerify Fix Applied:
Verify version is 9.7.1.29511 or higher in Help > About Foxit Reader📡 Detection & Monitoring
Log Indicators:
- Process creation events for unexpected executables from Foxit Reader
- Crash logs from Foxit Reader with memory access violations
Network Indicators:
- Outbound connections from Foxit Reader process to suspicious IPs
- DNS requests for known malicious domains from Foxit Reader
SIEM Query:
source="windows" AND process_name="FoxitReader.exe" AND (event_id=1 OR event_id=4688) AND parent_process_name="explorer.exe" AND command_line LIKE "%.jp2" OR command_line LIKE "%.j2k"