CVE-2021-22702
📋 TL;DR
This vulnerability allows attackers to intercept Telnet communications between users and affected Schneider Electric PowerLogic/ION power monitoring devices, exposing user credentials transmitted in cleartext. Attackers can capture usernames and passwords when monitoring network traffic. Organizations using these specific power monitoring devices with Telnet enabled are affected.
💻 Affected Systems
- PowerLogic ION7400
- ION7650
- ION7700/73xx
- ION83xx/84xx/85xx/8600
- ION8650
- ION8800
- ION9000
- PM800
📦 What is this software?
Powerlogic Ion7300 Firmware by Schneider Electric
Powerlogic Ion7400 Firmware by Schneider Electric
Powerlogic Ion7650 Firmware by Schneider Electric
Powerlogic Ion7700 Firmware by Schneider Electric
Powerlogic Ion8300 Firmware by Schneider Electric
Powerlogic Ion8400 Firmware by Schneider Electric
Powerlogic Ion8500 Firmware by Schneider Electric
Powerlogic Ion8600 Firmware by Schneider Electric
Powerlogic Ion8650 Firmware by Schneider Electric
Powerlogic Ion8800 Firmware by Schneider Electric
Powerlogic Ion9000 Firmware by Schneider Electric
Powerlogic Pm8000 Firmware by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain administrative credentials, compromise power monitoring systems, manipulate power readings, disrupt monitoring capabilities, or use devices as network footholds.
Likely Case
Attackers capture credentials during normal Telnet sessions, gain unauthorized access to devices, and potentially modify configurations or disrupt monitoring functions.
If Mitigated
With proper network segmentation and encrypted protocols, attackers cannot intercept credentials even if they gain network access.
🎯 Exploit Status
Exploitation requires network access to intercept Telnet traffic. No authentication needed to capture credentials in transit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Refer to Schneider Electric advisory SEVD-2021-040-01 for patched versions
Vendor Advisory: https://www.se.com/ww/en/download/document/SEVD-2021-040-01/
Restart Required: Yes
Instructions:
1. Review Schneider Electric advisory SEVD-2021-040-01. 2. Identify affected devices and versions. 3. Apply firmware updates provided by Schneider Electric. 4. Restart devices after patching. 5. Verify Telnet is disabled or replaced with encrypted protocols.
🔧 Temporary Workarounds
Disable Telnet Service
allDisable Telnet service on affected devices and use encrypted alternatives like SSH
Device-specific configuration commands to disable Telnet (consult device documentation)
Implement Network Segmentation
allIsolate affected devices on separate VLANs with strict access controls
🧯 If You Can't Patch
- Disable Telnet service completely and use SSH or other encrypted protocols for device management
- Implement network segmentation and access controls to restrict who can communicate with affected devices
🔍 How to Verify
Check if Vulnerable:
Check if Telnet service is enabled on affected devices and if firmware version matches affected versions in Schneider Electric advisoryCheck Version:
Device-specific command to check firmware version (consult device documentation)Verify Fix Applied:
Verify Telnet service is disabled or device firmware has been updated to patched version, then test that credentials are no longer transmitted in cleartext📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts
- Unusual Telnet connection patterns
- Configuration changes from unexpected sources
Network Indicators:
- Cleartext credential transmission on port 23
- Unusual network traffic to/from power monitoring devices
- Telnet sessions from unexpected IP addresses
SIEM Query:
source_port:23 AND (protocol:telnet) AND (event_description:"authentication" OR "login")