CVE-2020-28221
📋 TL;DR
This vulnerability allows remote attackers to execute arbitrary code on affected HMI devices by exploiting improper input validation in the Ethernet Download feature. Attackers can gain full control of the device when this feature is enabled. This affects Schneider Electric EcoStruxure Operator Terminal Expert and Pro-face BLUE HMI products.
💻 Affected Systems
- EcoStruxure Operator Terminal Expert
- Pro-face BLUE
📦 What is this software?
Ecostruxure Operator Terminal Expert by Schneider Electric
View all CVEs affecting Ecostruxure Operator Terminal Expert →
Ecostruxure Operator Terminal Expert by Schneider Electric
View all CVEs affecting Ecostruxure Operator Terminal Expert →
Pro Face Blue by Schneider Electric
Pro Face Blue by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to install malware, disrupt industrial operations, pivot to other network systems, and potentially cause physical damage in industrial environments.
Likely Case
Remote code execution leading to data theft, system manipulation, and disruption of HMI operations affecting connected industrial processes.
If Mitigated
Limited impact if Ethernet Download feature is disabled and proper network segmentation is implemented.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with network-based attack vector and no authentication required. Exploitation likely straightforward once details are known.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions specified in SEVD-2021-012-01
Vendor Advisory: https://www.se.com/ww/en/download/document/SEVD-2021-012-01/
Restart Required: Yes
Instructions:
1. Download the patched firmware from Schneider Electric's security advisory page. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Restart the HMI device. 5. Verify the update was successful.
🔧 Temporary Workarounds
Disable Ethernet Download Feature
allDisable the vulnerable Ethernet Download functionality to prevent exploitation
Network Segmentation
allIsolate HMI devices in separate network segments with strict firewall rules
🧯 If You Can't Patch
- Disable Ethernet Download feature immediately
- Implement strict network access controls and segment HMI devices from untrusted networks
🔍 How to Verify
Check if Vulnerable:
Check if Ethernet Download feature is enabled in HMI configuration and verify firmware version against vulnerable versions in SEVD-2021-012-01Check Version:
Check firmware version through HMI device interface or management consoleVerify Fix Applied:
Verify firmware version matches patched version from advisory and confirm Ethernet Download feature is disabled or patched📡 Detection & Monitoring
Log Indicators:
- Unexpected Ethernet Download activity
- Unauthorized firmware update attempts
- Unusual network connections to HMI ports
Network Indicators:
- Suspicious traffic to HMI Ethernet Download ports
- Unexpected firmware transfer packets
SIEM Query:
source_ip:external AND dest_port:HMI_ports AND protocol:TCP AND (event_type:download OR file_transfer)