CVE-2020-7475
📋 TL;DR
This vulnerability allows attackers to inject malicious code into Schneider Electric PLC controllers through improper input validation in engineering software. It affects EcoStruxure Control Expert, Unity Pro, and Modicon M340/M580 controllers. Successful exploitation could enable remote code execution on industrial control systems.
💻 Affected Systems
- EcoStruxure Control Expert
- Unity Pro
- Modicon M340
- Modicon M580
📦 What is this software?
Ecostruxure Control Expert by Schneider Electric
Modicon M340 Firmware by Schneider Electric
Modicon M580 Firmware by Schneider Electric
Unity Pro by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems leading to physical process disruption, equipment damage, or safety incidents through malicious code execution on PLCs.
Likely Case
Unauthorized access to PLC logic, manipulation of industrial processes, or installation of persistent malware in control systems.
If Mitigated
Limited impact through network segmentation and access controls preventing exploitation attempts.
🎯 Exploit Status
Requires access to engineering software and network connectivity to controllers; reflective DLL injection technique.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Control Expert 14.1 Hot Fix, M340 V3.20, M580 V3.10
Vendor Advisory: http://www.se.com/ww/en/download/document/SEVD-2020-080-01
Restart Required: Yes
Instructions:
1. Download patches from Schneider Electric security advisory. 2. Apply Control Expert hot fix. 3. Update M340 firmware to V3.20. 4. Update M580 firmware to V3.10. 5. Restart affected systems.
🔧 Temporary Workarounds
Network Segmentation
allIsolate PLC networks from engineering stations and corporate networks
Access Control
windowsRestrict engineering software access to authorized personnel only
🧯 If You Can't Patch
- Implement strict network segmentation between engineering workstations and PLC controllers
- Apply principle of least privilege to engineering software access and monitor for unauthorized transfers
🔍 How to Verify
Check if Vulnerable:
Check software versions: Control Expert < 14.1 Hot Fix, M340 firmware < V3.20, M580 firmware < V3.10Check Version:
In Control Expert: Help → About; For PLCs: Connect and check firmware version in programming softwareVerify Fix Applied:
Confirm Control Expert version includes hot fix, M340 firmware ≥ V3.20, M580 firmware ≥ V3.10📡 Detection & Monitoring
Log Indicators:
- Unauthorized engineering software access
- Unexpected code transfers to PLCs
- Failed authentication attempts to engineering stations
Network Indicators:
- Unexpected traffic between engineering stations and PLCs
- Protocol anomalies in Modbus/TCP communications
SIEM Query:
source="engineering_station" AND dest="plc_network" AND (action="code_transfer" OR protocol="modbus")