CVE-2021-44462
📋 TL;DR
CVE-2021-44462 is a memory corruption vulnerability in Horner Automation Cscape EnvisionRV software versions v4.50.3.1 and prior. Attackers can exploit this by tricking users into opening malicious HMI project files, potentially leading to arbitrary code execution. This affects industrial control system operators using vulnerable versions of the software.
💻 Affected Systems
- Horner Automation Cscape EnvisionRV
📦 What is this software?
Cscape Envisionrv by Hornerautomation
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with attacker gaining full control of the HMI system, potentially disrupting industrial processes or enabling lateral movement within OT networks.
Likely Case
Application crash or denial of service affecting HMI functionality, with potential for limited code execution in the context of the Cscape EnvisionRV process.
If Mitigated
No impact if malicious project files are prevented from reaching users or if software is patched/updated.
🎯 Exploit Status
Exploitation requires social engineering to deliver malicious project files and user interaction to open them.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v4.50.3.2 or later
Vendor Advisory: https://www.hornerautomation.com/security-advisories
Restart Required: Yes
Instructions:
1. Download latest version from Horner Automation website. 2. Run installer. 3. Restart system. 4. Verify version is v4.50.3.2 or higher.
🔧 Temporary Workarounds
Restrict project file handling
windowsImplement application whitelisting to prevent execution of Cscape EnvisionRV from untrusted locations or block .hmi project file extensions.
Using Windows AppLocker or similar: Create rule to allow Cscape EnvisionRV only from trusted paths.
User training and file validation
allTrain operators to only open project files from trusted sources and implement file validation procedures.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate HMI systems from untrusted networks
- Use application control solutions to restrict which users can run Cscape EnvisionRV and from which locations
🔍 How to Verify
Check if Vulnerable:
Check Help > About in Cscape EnvisionRV - if version is v4.50.3.1 or lower, system is vulnerable.Check Version:
In Cscape EnvisionRV: Help > About displays version informationVerify Fix Applied:
Verify version is v4.50.3.2 or higher in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes of Cscape EnvisionRV
- Unexpected process termination events
- Security logs showing blocked execution attempts
Network Indicators:
- Unusual file transfers to HMI systems
- Email attachments with .hmi extensions being delivered
SIEM Query:
EventID=1000 OR EventID=1001 Source='Cscape EnvisionRV' OR FileExtension='.hmi' AND Process='Cscape EnvisionRV'