CVE-2021-22683
📋 TL;DR
CVE-2021-22683 is an out-of-bounds write vulnerability in Fatek FvDesigner software that allows arbitrary code execution when processing malicious project files. This affects industrial control system engineers and organizations using Fatek PLC programming software. Attackers can achieve remote code execution by tricking users into opening specially crafted project files.
💻 Affected Systems
- Fatek FvDesigner
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of engineering workstation leading to lateral movement into industrial control networks, manipulation of PLC logic, and potential physical process disruption.
Likely Case
Compromise of engineering workstation allowing theft of intellectual property, credential harvesting, and establishing foothold for further attacks.
If Mitigated
Isolated compromise of single workstation with limited impact due to network segmentation and restricted privileges.
🎯 Exploit Status
Exploitation requires user interaction to open malicious project file; no authentication bypass needed.
🛠️ 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 via application control or group policy
Using AppLocker: New-AppLockerPolicy -RuleType Path -Action Deny -Path "*.fvp" -User Everyone
User training and file validation
allTrain users to only open project files from trusted sources and validate file integrity
🧯 If You Can't Patch
- Network segmentation: Isolate engineering workstations from general corporate network and internet
- Least privilege: Run FvDesigner with restricted user accounts, disable administrative privileges
🔍 How to Verify
Check if Vulnerable:
Check FvDesigner version via Help > About menu; versions 1.5.76 or earlier are vulnerableCheck Version:
Not applicable - check via GUI onlyVerify Fix Applied:
Verify version is 1.5.77 or later in Help > About menu📡 Detection & Monitoring
Log Indicators:
- Unexpected process crashes of FvDesigner.exe
- Creation of suspicious child processes from FvDesigner
Network Indicators:
- Outbound connections from engineering workstations to unexpected destinations
SIEM Query:
Process Creation where Image ends with 'FvDesigner.exe' and CommandLine contains suspicious patterns