CVE-2023-27366
📋 TL;DR
This is a use-after-free vulnerability in Foxit PDF Reader's Doc object handling that allows remote attackers to execute arbitrary code. Attackers can exploit it by tricking users into opening malicious PDF files or visiting malicious web pages. All users running vulnerable versions of Foxit PDF Reader are affected.
💻 Affected Systems
- Foxit PDF Reader
📦 What is this software?
⚠️ 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
Local privilege escalation leading to malware installation, credential theft, or data exfiltration from the compromised system.
If Mitigated
Limited impact due to sandboxing or application hardening, potentially resulting in application crash rather than code execution.
🎯 Exploit Status
ZDI published details but no public exploit code. User interaction required but exploitation is straightforward once malicious file is opened.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 12.1.2.15332 and later
Vendor Advisory: https://www.foxit.com/support/security-bulletins.html
Restart Required: Yes
Instructions:
1. Open Foxit PDF Reader. 2. Go to Help > Check for Updates. 3. Follow prompts to download and install version 12.1.2.15332 or later. 4. Restart the application.
🔧 Temporary Workarounds
Disable JavaScript in Foxit Reader
windowsPrevents JavaScript-based exploitation vectors
Open Foxit Reader > File > Preferences > JavaScript > Uncheck 'Enable JavaScript'
Use Protected View
windowsOpens files in restricted mode to limit damage
Open Foxit Reader > File > Preferences > Trust Manager > Check 'Enable Safe Reading Mode'
🧯 If You Can't Patch
- Block PDF files from untrusted sources at email/web gateways
- Use alternative PDF readers that are not vulnerable
🔍 How to Verify
Check if Vulnerable:
Open Foxit Reader, go to Help > About Foxit Reader and check if version is below 12.1.2.15332Check Version:
wmic product where name="Foxit Reader" get versionVerify Fix Applied:
Confirm version is 12.1.2.15332 or higher in Help > About Foxit Reader📡 Detection & Monitoring
Log Indicators:
- Application crashes with memory access violations
- Unexpected child processes spawned from Foxit Reader
Network Indicators:
- Outbound connections from Foxit Reader to unusual destinations
- DNS requests for suspicious domains after PDF opening
SIEM Query:
process_name="FoxitReader.exe" AND (event_id=1000 OR child_process_creation=true)