CVE-2023-24304
📋 TL;DR
This vulnerability allows attackers to execute arbitrary code on systems running IrfanView by tricking users into opening a malicious PDF file. The improper input validation in the PDF.dll plugin enables remote code execution. All users of IrfanView v4.60 are affected.
💻 Affected Systems
- IrfanView
📦 What is this software?
Irfanview by Irfanview
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control over the victim's machine, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Malware installation or data exfiltration when users open malicious PDF files, often delivered via phishing emails or compromised websites.
If Mitigated
Limited impact if proper application whitelisting, least privilege principles, and network segmentation are implemented.
🎯 Exploit Status
Exploitation requires user interaction (opening a malicious PDF) but no authentication. The CWE-20 (Improper Input Validation) suggests straightforward exploitation once the vulnerability is understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v4.61 or later
Vendor Advisory: https://www.irfanview.com/main_history.htm
Restart Required: No
Instructions:
1. Download IrfanView v4.61 or later from the official website. 2. Run the installer. 3. Follow installation prompts to update. 4. Verify the version in Help > About IrfanView.
🔧 Temporary Workarounds
Disable PDF plugin
windowsRemove or disable the vulnerable PDF.dll plugin to prevent exploitation
Move or rename PDF.dll in IrfanView's plugins directory
Block PDF file association
windowsPrevent IrfanView from opening PDF files by default
Use Windows Settings > Apps > Default apps to change PDF association to another application
🧯 If You Can't Patch
- Implement application control policies to block IrfanView execution
- Use network segmentation to isolate systems running vulnerable versions
🔍 How to Verify
Check if Vulnerable:
Check IrfanView version in Help > About IrfanView. If version is 4.60, the system is vulnerable.Check Version:
Not applicable - check via GUI in Help > AboutVerify Fix Applied:
Verify IrfanView version is 4.61 or later in Help > About IrfanView.📡 Detection & Monitoring
Log Indicators:
- IrfanView crash logs, unexpected process creation from IrfanView, suspicious PDF file access
Network Indicators:
- Downloads of PDF files from untrusted sources, network connections from IrfanView to suspicious IPs
SIEM Query:
Process creation where parent process contains 'i_view' and child process is suspicious