CVE-2021-38430
📋 TL;DR
CVE-2021-38430 is a stack-based buffer overflow vulnerability in FATEK Automation WinProladder software versions 3.30 and prior. Attackers can exploit this by crafting malicious project files to execute arbitrary code on affected systems. This primarily impacts industrial control system (ICS) environments using FATEK PLC programming software.
💻 Affected Systems
- FATEK Automation WinProladder
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise allowing attackers to execute arbitrary code with the privileges of the WinProladder process, potentially leading to PLC reprogramming, process disruption, or lateral movement within OT networks.
Likely Case
Local code execution on engineering workstations, potentially disrupting PLC programming operations and compromising project files.
If Mitigated
Limited impact if proper network segmentation and file validation controls prevent malicious project files from reaching vulnerable systems.
🎯 Exploit Status
Exploitation requires user interaction to open malicious project files. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 3.31 or later
Vendor Advisory: https://us-cert.cisa.gov/ics/advisories/icsa-21-280-06
Restart Required: Yes
Instructions:
1. Download WinProladder version 3.31 or later from FATEK Automation website. 2. Uninstall current version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Restrict project file handling
windowsConfigure Windows to open .prl files with a text editor instead of WinProladder by default
Right-click .prl file > Open with > Choose another app > Select Notepad > Check 'Always use this app'
Application whitelisting
windowsUse Windows AppLocker or similar to restrict execution of WinProladder to authorized users only
🧯 If You Can't Patch
- Implement strict network segmentation to isolate WinProladder systems from untrusted networks
- Train users to only open project files from trusted sources and implement file hash verification procedures
🔍 How to Verify
Check if Vulnerable:
Check WinProladder version via Help > About menu. If version is 3.30 or earlier, system is vulnerable.Check Version:
No command-line option. Use GUI: Help > About in WinProladder application.Verify Fix Applied:
After update, verify version shows 3.31 or later in Help > About menu.📡 Detection & Monitoring
Log Indicators:
- Application crashes of WinProladder.exe
- Unusual process creation from WinProladder
- Multiple failed file parsing attempts
Network Indicators:
- Unusual file transfers to engineering workstations
- SMB/NFS connections from untrusted sources to systems running WinProladder
SIEM Query:
Process:WinProladder.exe AND (EventID:1000 OR EventID:1001) OR FileExtension:.prl AND SourceIP:External