CVE-2020-7548
📋 TL;DR
This vulnerability allows unauthorized users to bypass authentication and gain access to Schneider Electric Smartlink, PowerTag, and Wiser Series Gateways due to insufficient randomness in security mechanisms. Attackers can exploit predictable values to login without valid credentials. Organizations using these industrial control system gateways are affected.
💻 Affected Systems
- Smartlink Gateway
- PowerTag Gateway
- Wiser Series Gateway
📦 What is this software?
Acti9 Powertag Link Firmware by Schneider Electric
Acti9 Powertag Link Hd Firmware by Schneider Electric
Acti9 Smartlink El B Firmware by Schneider Electric
Acti9 Smartlink Si B Firmware by Schneider Electric
Acti9 Smartlink Si D Firmware by Schneider Electric
Wiser Energy Firmware by Schneider Electric
Wiser Link Firmware by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems, allowing attackers to manipulate critical infrastructure operations, disrupt power distribution, or cause physical damage.
Likely Case
Unauthorized access to gateway management interfaces, enabling configuration changes, data theft, or disruption of monitoring systems.
If Mitigated
Limited impact if gateways are isolated in protected networks with strict access controls and monitoring.
🎯 Exploit Status
Exploitation requires network access to the gateway but no authentication. Attack methodology is straightforward once understood.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions specified in SEVD-2020-287-03 advisory
Vendor Advisory: https://www.se.com/ww/en/download/document/SEVD-2020-287-03/
Restart Required: Yes
Instructions:
1. Download firmware update from Schneider Electric website. 2. Backup current configuration. 3. Apply firmware update via web interface or management tool. 4. Restart gateway. 5. Verify update successful.
🔧 Temporary Workarounds
Network Segmentation
allIsolate gateways in protected network segments with strict firewall rules
Access Control Lists
allImplement strict IP-based access controls to limit who can connect to gateway interfaces
🧯 If You Can't Patch
- Implement network segmentation to isolate gateways from untrusted networks
- Enable detailed logging and monitoring for authentication attempts and configuration changes
🔍 How to Verify
Check if Vulnerable:
Check gateway firmware version against vulnerable versions listed in SEVD-2020-287-03Check Version:
Check via web interface: System > About or use SNMP queries for version informationVerify Fix Applied:
Verify firmware version matches patched versions in advisory and test authentication with invalid credentials📡 Detection & Monitoring
Log Indicators:
- Failed login attempts followed by successful login from same source
- Authentication events with unusual timing patterns
- Configuration changes from unexpected sources
Network Indicators:
- Unusual authentication traffic patterns
- Connection attempts to gateway management ports from unexpected sources
SIEM Query:
source="gateway" AND (event_type="authentication" AND result="success") AND NOT user IN [authorized_users]