CVE-2021-22772
📋 TL;DR
This vulnerability allows attackers to bypass authentication on Schneider Electric Easergy T200 devices, enabling unauthorized control of critical power management systems. It affects Easergy T200 devices with specific firmware versions across Modbus, IEC104, and DNP3 communication protocols. Organizations using these devices for electrical grid or industrial control systems are at risk.
💻 Affected Systems
- Easergy T200 (Modbus)
- Easergy T200 (IEC104)
- Easergy T200 (DNP3)
📦 What is this software?
T200e Firmware by Schneider Electric
T200e Firmware by Schneider Electric
T200e Firmware by Schneider Electric
T200i Firmware by Schneider Electric
T200i Firmware by Schneider Electric
T200i Firmware by Schneider Electric
T200p Firmware by Schneider Electric
T200p Firmware by Schneider Electric
T200p Firmware by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete takeover of power management systems leading to grid instability, equipment damage, or power outages affecting critical infrastructure.
Likely Case
Unauthorized configuration changes, disruption of power monitoring, or manipulation of control commands in industrial environments.
If Mitigated
Limited impact if devices are isolated in protected networks with strict access controls and monitoring.
🎯 Exploit Status
The vulnerability description indicates authentication bypass, suggesting relatively straightforward exploitation once the attack vector is identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after those listed in affected systems
Vendor Advisory: http://download.schneider-electric.com/files?p_Doc_Ref=SEVD-2021-194-05
Restart Required: Yes
Instructions:
1. Download updated firmware from Schneider Electric portal. 2. Backup current configuration. 3. Apply firmware update following vendor instructions. 4. Verify update completion and restore configuration if needed. 5. Test functionality.
🔧 Temporary Workarounds
Network segmentation
allIsolate Easergy T200 devices in dedicated network segments with strict firewall rules.
Access control lists
allImplement strict IP-based access controls allowing only authorized management systems to communicate with devices.
🧯 If You Can't Patch
- Implement network-level authentication using VPNs or jump hosts for all device access
- Deploy intrusion detection systems monitoring for unauthorized access attempts to these devices
🔍 How to Verify
Check if Vulnerable:
Check device firmware version via web interface or serial console and compare against affected versions listed in vendor advisory.Check Version:
Device-specific commands vary; typically accessed via web interface at device IP or serial console connection.Verify Fix Applied:
Verify firmware version is updated beyond affected versions and test authentication requirements for critical functions.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts
- Configuration changes from unexpected sources
- Authentication bypass attempts
Network Indicators:
- Unusual traffic patterns to device ports
- Connection attempts from unauthorized IP addresses
- Protocol anomalies in Modbus/IEC104/DNP3 communications
SIEM Query:
source_ip=* AND (dest_port=502 OR dest_port=2404) AND (protocol="modbus" OR protocol="iec104" OR protocol="dnp3") AND action="write" OR action="configure"