CVE-2021-21793
📋 TL;DR
This vulnerability allows remote code execution through memory corruption when processing malicious JPG files in Accusoft ImageGear. Attackers can exploit this by tricking users or systems into opening specially crafted image files. Organizations using ImageGear 19.8-19.9 for image processing are affected.
💻 Affected Systems
- Accusoft ImageGear
📦 What is this software?
Imagegear by Accusoft
Imagegear by Accusoft
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with arbitrary code execution, potentially leading to data theft, ransomware deployment, or lateral movement within the network.
Likely Case
Application crash leading to denial of service, with potential for limited code execution depending on exploit sophistication.
If Mitigated
Application crash with no code execution if memory protections like ASLR/DEP are properly implemented and effective.
🎯 Exploit Status
Exploitation requires user interaction to open malicious file or automated processing of uploaded files. The vulnerability is in header parsing, making reliable exploitation possible.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 19.10 or later
Vendor Advisory: https://www.accusoft.com/products/imagegear/
Restart Required: Yes
Instructions:
1. Download ImageGear 19.10 or later from Accusoft website. 2. Uninstall current ImageGear version. 3. Install updated version. 4. Restart affected systems. 5. Recompile any applications using ImageGear libraries.
🔧 Temporary Workarounds
File Type Restriction
allBlock or restrict processing of JPG files in applications using ImageGear
Application Sandboxing
allRun ImageGear applications in restricted environments with limited permissions
🧯 If You Can't Patch
- Implement strict file upload validation and scanning for JPG files
- Deploy application control to prevent execution of unknown binaries from ImageGear processes
🔍 How to Verify
Check if Vulnerable:
Check ImageGear version in installed programs list or application dependencies. Versions 19.8-19.9 are vulnerable.Check Version:
On Windows: Check Programs and Features. On Linux: Check package manager or library version.Verify Fix Applied:
Verify ImageGear version is 19.10 or later. Test with known malicious JPG files to ensure proper error handling.📡 Detection & Monitoring
Log Indicators:
- Application crashes from ImageGear processes
- Memory access violation errors in application logs
- Unexpected process termination
Network Indicators:
- Unusual outbound connections from ImageGear processes
- File uploads to image processing endpoints
SIEM Query:
source="*ImageGear*" AND (event_type="crash" OR event_type="access_violation")