CVE-2020-13561
📋 TL;DR
An out-of-bounds write vulnerability in the TIFF parser of Accusoft ImageGear 19.8 allows remote code execution via specially crafted TIFF files. This affects any application using the vulnerable ImageGear library to process TIFF images. Attackers can exploit this by tricking users into opening malicious files.
💻 Affected Systems
- Accusoft ImageGear
📦 What is this software?
Imagegear by Accusoft
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with attacker gaining the same privileges as the user running the vulnerable application, potentially leading to data theft, ransomware deployment, or persistent backdoor installation.
Likely Case
Remote code execution in the context of the application user, allowing file system access, data exfiltration, and lateral movement within the network.
If Mitigated
Application crash or denial of service if memory corruption doesn't lead to successful code execution.
🎯 Exploit Status
The vulnerability requires user interaction to open a malicious file, but exploitation is straightforward once the file is processed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 19.9 or later
Vendor Advisory: https://www.accusoft.com/products/imagegear/
Restart Required: Yes
Instructions:
1. Upgrade to ImageGear version 19.9 or later. 2. Rebuild any applications using the ImageGear library. 3. Restart affected services and applications.
🔧 Temporary Workarounds
Disable TIFF file processing
allConfigure applications to reject or not process TIFF files
Application sandboxing
allRun vulnerable applications with reduced privileges or in isolated environments
🧯 If You Can't Patch
- Implement strict file upload filtering to block TIFF files
- Use application allowlisting to prevent execution of untrusted applications
🔍 How to Verify
Check if Vulnerable:
Check if any applications use ImageGear library version 19.8 or earlier. Review application dependencies and vendor documentation.Check Version:
Check application documentation or contact vendor for version verification methodsVerify Fix Applied:
Verify ImageGear library version is 19.9 or later. Test with known malicious TIFF files to ensure they are rejected or processed safely.📡 Detection & Monitoring
Log Indicators:
- Application crashes when processing TIFF files
- Unexpected process creation from image processing applications
- Memory access violation errors
Network Indicators:
- Unusual outbound connections from image processing applications
- TIFF file downloads from untrusted sources
SIEM Query:
source="application_logs" AND ("ImageGear" OR "TIFF") AND ("crash" OR "access violation" OR "memory corruption")