CVE-2022-29958
📋 TL;DR
CVE-2022-29958 allows unauthenticated attackers to execute arbitrary machine code on JTEKT TOYOPUC PLCs by exploiting the unauthenticated CMPLink/TCP protocol used for engineering functions. This gives attackers full control over the PLC's CPU module since these devices lack memory protection mechanisms. Organizations using TOYOPUC PLCs in industrial control systems are affected.
💻 Affected Systems
- JTEKT TOYOPUC PLCs
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial processes, allowing attackers to manipulate physical equipment, cause equipment damage, disrupt operations, or create safety hazards.
Likely Case
Unauthorized modification of control logic leading to process disruption, data manipulation, or industrial espionage.
If Mitigated
Limited impact if network segmentation and access controls prevent attackers from reaching PLCs.
🎯 Exploit Status
Exploitation requires network access to PLC but no authentication. The protocol is documented for engineering use.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.cisa.gov/uscert/ics/advisories/icsa-22-172-02
Restart Required: No
Instructions:
No official patch available. Follow CISA ICS advisory recommendations for mitigation.
🔧 Temporary Workarounds
Network Segmentation
allIsolate TOYOPUC PLCs in dedicated network segments with strict access controls.
Firewall Rules
allBlock CMPLink/TCP protocol (default port 102) from all unauthorized networks and hosts.
🧯 If You Can't Patch
- Implement strict network segmentation with industrial DMZs
- Deploy intrusion detection systems monitoring for CMPLink/TCP traffic anomalies
🔍 How to Verify
Check if Vulnerable:
Check if TOYOPUC PLCs are accessible on network and if CMPLink/TCP port 102 is open and accessible.Check Version:
Consult PLC configuration or vendor documentation for firmware version.Verify Fix Applied:
Verify network segmentation prevents unauthorized access to PLCs and CMPLink/TCP traffic is blocked.📡 Detection & Monitoring
Log Indicators:
- Unauthorized CMPLink/TCP connection attempts
- Unexpected engineering workstation connections
Network Indicators:
- CMPLink/TCP traffic from unauthorized IPs
- Port 102 scans or connections
SIEM Query:
source_port:102 OR dest_port:102 AND (NOT authorized_source_ip)