CVE-2020-27281
📋 TL;DR
This vulnerability allows remote code execution via a stack-based buffer overflow in Delta Electronics CNCSoft ScreenEditor when processing malicious project files. Attackers can exploit this to execute arbitrary code on affected systems. Users of CNCSoft ScreenEditor versions 1.01.26 and prior are affected.
💻 Affected Systems
- Delta Electronics CNCSoft ScreenEditor
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attacker to install malware, exfiltrate data, or disrupt industrial operations
Likely Case
Local privilege escalation or remote code execution leading to industrial control system compromise
If Mitigated
Limited impact through network segmentation and proper file handling controls
🎯 Exploit Status
Exploitation requires user to open a malicious project file; ZDI has published advisory with technical details
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 1.01.27 or later
Vendor Advisory: https://www.deltaww.com/en-US/Service/DownloadCenter
Restart Required: Yes
Instructions:
1. Download latest CNCSoft ScreenEditor from Delta Electronics website
2. Uninstall current version
3. Install updated version
4. Restart system
🔧 Temporary Workarounds
Restrict project file handling
windowsBlock or restrict opening of .scp project files from untrusted sources
Application whitelisting
windowsImplement application control to prevent unauthorized execution
🧯 If You Can't Patch
- Implement network segmentation to isolate CNC systems from business networks
- Use file integrity monitoring to detect unauthorized project file modifications
🔍 How to Verify
Check if Vulnerable:
Check CNCSoft ScreenEditor version in Help > About menuCheck Version:
Not applicable - check via application GUIVerify Fix Applied:
Confirm version is 1.01.27 or higher in Help > About menu📡 Detection & Monitoring
Log Indicators:
- Unexpected process crashes of CNCSoft ScreenEditor
- Unusual file access patterns to .scp files
Network Indicators:
- Unusual network connections from CNC systems
- File transfers containing .scp files
SIEM Query:
EventID=1000 Source=CNCSoft* OR ProcessName=CNCSoft* AND ExceptionCode=0xC0000005