CVE-2020-7487
📋 TL;DR
CVE-2020-7487 is a critical vulnerability in Schneider Electric Modicon PLC controllers that allows attackers to execute arbitrary code by exploiting insufficient data authenticity verification. Attackers can potentially take full control of affected industrial controllers. This affects Modicon M218, M241, M251, and M258 programmable logic controllers.
💻 Affected Systems
- Modicon M218
- Modicon M241
- Modicon M251
- Modicon M258
📦 What is this software?
Ecostruxure Machine Expert by Schneider Electric
Modicon M218 Firmware by Schneider Electric
Modicon M241 Firmware by Schneider Electric
Modicon M251 Firmware by Schneider Electric
Modicon M258 Firmware by Schneider Electric
Somachine by Schneider Electric
Somachine Motion by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems allowing attackers to manipulate physical processes, cause equipment damage, disrupt operations, or create safety hazards in critical infrastructure.
Likely Case
Remote code execution leading to unauthorized control of industrial processes, data theft, or disruption of manufacturing operations.
If Mitigated
Limited impact if controllers are isolated in air-gapped networks with strict access controls and monitoring.
🎯 Exploit Status
Exploitation requires network access to controller but no authentication.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Schneider Electric security advisory SEVD-2020-105-02 for specific patched versions
Vendor Advisory: https://www.se.com/ww/en/download/document/SEVD-2020-105-02
Restart Required: Yes
Instructions:
1. Download firmware update from Schneider Electric website. 2. Backup controller configuration. 3. Apply firmware update using EcoStruxure Machine Expert. 4. Restart controller. 5. Verify firmware version.
🔧 Temporary Workarounds
Network Segmentation
allIsolate PLC controllers in dedicated network segments with strict firewall rules.
Access Control
allImplement strict network access controls allowing only authorized engineering stations to communicate with controllers.
🧯 If You Can't Patch
- Implement strict network segmentation and firewall rules to isolate controllers
- Monitor network traffic for unauthorized access attempts and anomalous communications
🔍 How to Verify
Check if Vulnerable:
Check controller firmware version against patched versions in Schneider Electric advisory SEVD-2020-105-02Check Version:
Use EcoStruxure Machine Expert to check controller firmware versionVerify Fix Applied:
Verify firmware version has been updated to patched version specified in vendor advisory📡 Detection & Monitoring
Log Indicators:
- Unauthorized firmware update attempts
- Unexpected controller restarts
- Anomalous network connections to controller ports
Network Indicators:
- Unexpected traffic to controller management ports
- Malformed packets targeting PLC protocols
SIEM Query:
source_ip IN (external_ips) AND dest_port IN (502, 1962, 44818) AND protocol IN (TCP, UDP)