CVE-2021-27458
📋 TL;DR
This vulnerability in JTEKT TOYOPUC industrial control systems allows attackers to disrupt Ethernet communications by leaving connections in an open state. If exploited, it prevents affected devices from establishing network connections with other devices. This affects multiple TOYOPUC product series used in industrial automation environments.
💻 Affected Systems
- TOYOPUC-PC10 Series
- TOYOPUC-Plus Series
- TOYOPUC-PC3J/PC2J Series
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete disruption of industrial control system communications leading to production downtime, safety system failures, or process control interruptions in critical infrastructure.
Likely Case
Temporary network communication failures between TOYOPUC devices, requiring manual intervention to restore connectivity and potentially causing production delays.
If Mitigated
Isolated network disruption affecting only specific devices with limited operational impact due to network segmentation and monitoring.
🎯 Exploit Status
Exploitation requires network access to affected devices and knowledge of link parameter settings. No public exploit code has been identified.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://us-cert.cisa.gov/ics/advisories/icsa-21-103-03
Restart Required: No
Instructions:
No official patch available. Follow CISA advisory recommendations for mitigation through network segmentation and access controls.
🔧 Temporary Workarounds
Network Segmentation
allIsolate TOYOPUC devices on separate network segments with strict firewall rules to limit attack surface.
Access Control Lists
allImplement strict network access controls to limit which devices can communicate with TOYOPUC systems.
🧯 If You Can't Patch
- Implement network monitoring to detect abnormal connection states and communication failures
- Establish incident response procedures for rapid recovery from network disruption events
🔍 How to Verify
Check if Vulnerable:
Check device model numbers against affected list and verify Ethernet communication functionalityCheck Version:
Consult device documentation or vendor for firmware version identification methodsVerify Fix Applied:
Test network connectivity between devices after implementing network segmentation controls📡 Detection & Monitoring
Log Indicators:
- Unexpected Ethernet connection state changes
- Failed communication attempts between devices
- Network interface errors
Network Indicators:
- Abnormal TCP connection states
- Unusual network traffic patterns to industrial control devices
- Communication timeouts between TOYOPUC devices
SIEM Query:
Search for network connection state anomalies or communication failures involving TOYOPUC device IP addresses