CVE-2022-34761
📋 TL;DR
A NULL pointer dereference vulnerability in Schneider Electric's X80 advanced RTU and OPC UA Modicon communication modules allows attackers to cause denial of service by sending malformed JSON content to the web server. This affects industrial control systems using these specific communication modules, potentially disrupting operational technology networks.
💻 Affected Systems
- X80 advanced RTU Communication Module (BMENOR2200H)
- OPC UA Modicon Communication Module (BMENUA0100)
📦 What is this software?
Opc Ua Module For M580 Firmware by Schneider Electric
X80 Advanced Rtu Module Firmware by Schneider Electric
⚠️ Risk & Real-World Impact
Worst Case
Complete denial of service of the web server component, disrupting communication and monitoring capabilities in industrial control systems, potentially affecting operational continuity.
Likely Case
Temporary web server crash requiring manual restart, causing brief loss of web-based monitoring and configuration access.
If Mitigated
Minimal impact with proper network segmentation and input validation controls in place.
🎯 Exploit Status
Exploitation requires sending specially crafted JSON content to the vulnerable web server endpoint.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific patched versions
Restart Required: Yes
Instructions:
1. Download firmware update from Schneider Electric portal. 2. Follow vendor's firmware update procedure for affected modules. 3. Restart devices after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices in separate network segments with strict access controls.
Input Validation
allImplement network-level JSON content validation using firewalls or web application firewalls.
🧯 If You Can't Patch
- Implement strict network access controls to limit access to web server ports
- Monitor for abnormal JSON payloads and web server restart events
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against affected versions listed in vendor advisory.Check Version:
Consult device documentation for version check command (typically via web interface or serial console).Verify Fix Applied:
Verify firmware version has been updated to patched version and test JSON parsing functionality.📡 Detection & Monitoring
Log Indicators:
- Web server crash logs
- Unexpected restarts of communication module services
- Failed JSON parsing errors
Network Indicators:
- Unusual JSON payloads sent to device web ports
- Multiple connection attempts to web server
SIEM Query:
source="device_logs" AND (event="crash" OR event="restart") AND process="webserver"🔗 References
- https://download.schneider-electric.com/files?p_enDocType=Security+and+Safety+Notice&p_File_Name=SEVD-2022-193-01_OPC_UA_X80_Advanced_RTU_Modicon_Communication_Modules+_Security_Notification.pdf
- https://download.schneider-electric.com/files?p_enDocType=Security+and+Safety+Notice&p_File_Name=SEVD-2022-193-01_OPC_UA_X80_Advanced_RTU_Modicon_Communication_Modules+_Security_Notification.pdf
