CVE-2021-29360
📋 TL;DR
This buffer overflow vulnerability in IrfanView allows attackers to execute arbitrary code by tricking users into opening a specially crafted RLE image file. The vulnerability affects IrfanView users who open untrusted image files, potentially leading to full system compromise.
💻 Affected Systems
- IrfanView
📦 What is this software?
Irfanview by Irfanview
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with SYSTEM/administrator privileges leading to complete system takeover, data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Local privilege escalation or arbitrary code execution in the context of the current user when opening a malicious RLE file, potentially leading to malware installation or data exfiltration.
If Mitigated
Limited impact with proper application sandboxing, user running with minimal privileges, and network segmentation preventing lateral movement.
🎯 Exploit Status
Exploitation requires user interaction to open a malicious file. Public research and proof-of-concept code exists in the provided GitHub repository.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: IrfanView 4.58 or later
Vendor Advisory: https://www.irfanview.com/main_history.htm
Restart Required: No
Instructions:
1. Download latest IrfanView from official website. 2. Run installer. 3. Follow installation prompts. 4. Verify version is 4.58 or higher.
🔧 Temporary Workarounds
Disable RLE file association
windowsRemove IrfanView as default handler for .rle files to prevent automatic exploitation
Control Panel > Default Programs > Set Associations > Find .rle > Change program
Application control policy
windowsBlock execution of IrfanView via application whitelisting or endpoint protection
🧯 If You Can't Patch
- Implement application sandboxing to limit IrfanView's system access
- Educate users to never open RLE files from untrusted sources and use alternative image viewers
🔍 How to Verify
Check if Vulnerable:
Check IrfanView version via Help > About. If version is 4.57 or earlier, system is vulnerable.Check Version:
irfanview.exe /?Verify Fix Applied:
Verify IrfanView version is 4.58 or later in Help > About dialog.📡 Detection & Monitoring
Log Indicators:
- IrfanView crash logs with exception in FORMATS module
- Windows Application logs showing IrfanView crashes
Network Indicators:
- Unusual outbound connections from IrfanView process
- Downloads of .rle files followed by IrfanView execution
SIEM Query:
process_name:"i_view32.exe" OR process_name:"i_view64.exe" AND (file_extension:".rle" OR crash_detected:true)