CVE-2022-29951
📋 TL;DR
CVE-2022-29951 is an authentication bypass vulnerability in JTEKT TOYOPUC PLCs that allows attackers to execute engineering functions without credentials. This affects all JTEKT TOYOPUC PLCs using the CMPLink/TCP protocol through April 29, 2022. Industrial organizations using these PLCs for automation and control systems are at risk.
💻 Affected Systems
- JTEKT TOYOPUC PLCs
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial processes allowing attackers to stop production, modify control logic, upload malicious projects, or cause physical damage to equipment.
Likely Case
Unauthorized access to PLC functions allowing attackers to disrupt operations, steal intellectual property (project files), or modify configurations.
If Mitigated
Limited impact if proper network segmentation and access controls prevent unauthorized access to PLC communication ports.
🎯 Exploit Status
The vulnerability requires no authentication and the protocol is documented, making exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: https://www.cisa.gov/uscert/ics/advisories/icsa-22-172-02
Restart Required: No
Instructions:
No official patch available. Follow vendor guidance and implement compensating controls as described in workarounds.
🔧 Temporary Workarounds
Network Segmentation
allIsolate PLCs in dedicated network segments with strict firewall rules limiting access to CMPLink/TCP ports.
Disable CMPLink/TCP
allDisable the CMPLink/TCP protocol if not required for operations.
Access Control Lists
allImplement network ACLs to restrict access to PLC ports only from authorized engineering stations.
🧯 If You Can't Patch
- Implement strict network segmentation to isolate PLCs from untrusted networks
- Deploy intrusion detection systems to monitor for unauthorized access attempts to PLC ports
🔍 How to Verify
Check if Vulnerable:
Check if JTEKT TOYOPUC PLCs are accessible on ports 1024-65534 via TCP or UDP and if CMPLink/TCP protocol is enabled.Check Version:
Check PLC firmware version through engineering software or physical interface. All versions through April 29, 2022 are affected.Verify Fix Applied:
Verify that network controls prevent unauthorized access to PLC ports and that only authorized systems can communicate with PLCs.📡 Detection & Monitoring
Log Indicators:
- Unauthorized connection attempts to PLC ports
- Unexpected engineering function calls
- Configuration changes from unauthorized sources
Network Indicators:
- Traffic to PLC ports from unauthorized IP addresses
- CMPLink/TCP protocol traffic from unexpected sources
SIEM Query:
source_ip NOT IN (authorized_ips) AND destination_port BETWEEN 1024 AND 65534 AND (protocol=tcp OR protocol=udp)