CVE-2021-21824
📋 TL;DR
This vulnerability allows an attacker to execute arbitrary code by exploiting an out-of-bounds write in Accusoft ImageGear's JPG processing. Attackers can trigger memory corruption via specially crafted JPEG files, potentially leading to remote code execution. Organizations using ImageGear 19.9 for image processing are affected.
💻 Affected Systems
- Accusoft ImageGear
📦 What is this software?
Imagegear by Accusoft
⚠️ Risk & Real-World Impact
Worst Case
Remote code execution with SYSTEM/root privileges leading to complete system compromise, data theft, and lateral movement.
Likely Case
Application crash (denial of service) or limited code execution within the application context.
If Mitigated
Application crash with no code execution if memory protections (ASLR, DEP) are effective.
🎯 Exploit Status
Proof-of-concept available in Talos advisory. Exploitation requires user/application to process malicious JPEG file.
🛠️ 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+ from Accusoft. 2. Uninstall vulnerable version. 3. Install patched version. 4. Restart affected systems.
🔧 Temporary Workarounds
Restrict JPEG file processing
allBlock or sandbox JPEG file processing in applications using ImageGear.
Application whitelisting
windowsUse application control to prevent execution of ImageGear DLLs from untrusted locations.
🧯 If You Can't Patch
- Isolate systems using ImageGear from internet and untrusted networks.
- Implement strict file upload validation rejecting malformed JPEGs.
🔍 How to Verify
Check if Vulnerable:
Check ImageGear version in installed programs or application dependencies.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 higher.📡 Detection & Monitoring
Log Indicators:
- Application crashes in ImageGear processes
- Memory access violation errors
Network Indicators:
- Unusual outbound connections after JPEG file processing
SIEM Query:
ImageGear.exe OR ig*.dll AND (EventID=1000 OR "access violation")