CVE-2023-49140
📋 TL;DR
This vulnerability allows remote unauthenticated attackers to cause denial-of-service conditions in HMI GC-A2 series devices by sending specially crafted packets to specific ports. The commplex-link service becomes unresponsive, disrupting human-machine interface functionality. Organizations using affected HMI GC-A2 devices are at risk.
💻 Affected Systems
- HMI GC-A2 series
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of HMI GC-A2 devices, potentially affecting industrial control systems and manufacturing operations that rely on these interfaces.
Likely Case
Temporary service interruption requiring device restart, causing operational downtime in industrial environments.
If Mitigated
Minimal impact with proper network segmentation and monitoring in place to detect and block malicious traffic.
🎯 Exploit Status
Exploitation requires sending crafted packets to specific ports, which is relatively simple for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check vendor advisory for specific firmware versions
Vendor Advisory: https://www.electronics.jtekt.co.jp/en/topics/202312116562/
Restart Required: Yes
Instructions:
1. Download latest firmware from JTEKT Electronics website. 2. Follow vendor's firmware update procedure for HMI GC-A2 devices. 3. Restart devices after update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate HMI devices from untrusted networks using firewalls or VLANs
Port Blocking
allBlock access to the specific ports used by commplex-link service from untrusted sources
🧯 If You Can't Patch
- Implement strict network access controls to limit which systems can communicate with HMI devices
- Deploy network intrusion detection systems to monitor for DoS attack patterns targeting HMI ports
🔍 How to Verify
Check if Vulnerable:
Check device firmware version against vendor advisory. If running vulnerable version and commplex-link service is enabled, device is vulnerable.Check Version:
Check device firmware version through HMI interface or vendor-specific management toolsVerify Fix Applied:
Verify firmware version matches patched version from vendor advisory and test service functionality.📡 Detection & Monitoring
Log Indicators:
- Unusual traffic spikes to HMI ports
- Service restart events
- Connection failures to commplex-link service
Network Indicators:
- High volume of malformed packets to specific HMI ports
- Traffic patterns matching DoS attack signatures
SIEM Query:
source_ip:external AND dest_port:[HMI_PORT_RANGE] AND packet_size:anomalous