CVE-2021-22666
📋 TL;DR
CVE-2021-22666 is a stack-based buffer overflow vulnerability in Fatek FvDesigner software that allows attackers to execute arbitrary code by crafting malicious project files. This affects industrial control system engineers and organizations using Fatek PLC programming software. Successful exploitation could compromise engineering workstations and potentially affect connected industrial processes.
💻 Affected Systems
- Fatek FvDesigner
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of engineering workstation leading to lateral movement within OT network, manipulation of PLC logic, and potential physical process disruption.
Likely Case
Compromise of engineering workstation leading to data theft, credential harvesting, and establishment of persistent access in OT environment.
If Mitigated
Isolated compromise of single workstation with limited impact due to network segmentation and restricted user privileges.
🎯 Exploit Status
Exploitation requires user to open malicious project file; buffer overflow leads to arbitrary code execution with user privileges.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.5.77 or later
Vendor Advisory: https://us-cert.cisa.gov/ics/advisories/icsa-21-056-02
Restart Required: Yes
Instructions:
1. Download latest version from Fatek website. 2. Uninstall current version. 3. Install updated version. 4. Restart system.
🔧 Temporary Workarounds
Restrict project file execution
windowsBlock execution of .fvp project files or restrict to trusted sources only
Application whitelisting
windowsImplement application control to only allow execution of verified FvDesigner binaries
🧯 If You Can't Patch
- Implement strict file validation: Only open project files from trusted sources and verify file integrity
- Network segmentation: Isolate engineering workstations from production networks and implement strict firewall rules
🔍 How to Verify
Check if Vulnerable:
Check FvDesigner version in Help > About menu; versions 1.5.76 or earlier are vulnerableCheck Version:
Not applicable - check via application GUIVerify Fix Applied:
Verify version is 1.5.77 or later in Help > About menu📡 Detection & Monitoring
Log Indicators:
- Application crashes of FvDesigner.exe
- Unusual process creation from FvDesigner
- Execution of unexpected binaries
Network Indicators:
- Unusual outbound connections from engineering workstation
- Lateral movement attempts from engineering workstation
SIEM Query:
Process Creation where Image contains 'FvDesigner.exe' and CommandLine contains unusual parameters