CVE-2025-9466 Overview
A denial-of-service vulnerability exists within Rockwell Automation ArmorStart® LT motor controllers. During execution of the Achilles EtherNet/IP and CIP grammar tests, the device reboots unexpectedly, causing the Link State Monitor to go down for several seconds. This vulnerability allows remote attackers to disrupt industrial control system operations without requiring authentication.
Critical Impact
Remote attackers can cause unexpected device reboots in industrial environments, disrupting critical manufacturing and automation processes through network-accessible EtherNet/IP protocol exploitation.
Affected Products
- Rockwell Automation ArmorStart® LT Motor Controllers
- Industrial control systems utilizing EtherNet/IP protocol
- Devices implementing CIP (Common Industrial Protocol)
Discovery Timeline
- 2026-01-20 - CVE CVE-2025-9466 published to NVD
- 2026-01-20 - Last updated in NVD database
Technical Details for CVE-2025-9466
Vulnerability Analysis
This vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the ArmorStart® LT device fails to properly manage resources when processing specially crafted network traffic. The flaw manifests during EtherNet/IP and CIP protocol grammar testing, suggesting inadequate input validation or resource management in the protocol handling code.
The vulnerability allows network-based attackers to trigger unexpected device reboots without requiring any privileges or user interaction. When exploited, the Link State Monitor goes down for several seconds, which can have cascading effects in industrial automation environments where continuous operation is critical.
Root Cause
The root cause stems from improper resource consumption handling (CWE-400) in the ArmorStart® LT firmware's EtherNet/IP and CIP protocol implementation. When the device processes certain protocol grammar patterns discovered through Achilles testing, it fails to properly manage internal resources, leading to a system reboot. This indicates insufficient bounds checking or memory management in the protocol parsing routines.
Attack Vector
The attack vector is network-based, targeting the EtherNet/IP protocol interface exposed by ArmorStart® LT devices. An attacker with network access to the device can send malformed or specially crafted CIP protocol messages that trigger the vulnerability. The attack requires:
- Network connectivity to the target ArmorStart® LT device
- Ability to send EtherNet/IP protocol traffic (typically port 44818 TCP/UDP)
- No authentication or user interaction required
The vulnerability was identified through Achilles EtherNet/IP and CIP grammar fuzzing tests, indicating that malformed protocol messages can trigger the denial-of-service condition.
Detection Methods for CVE-2025-9466
Indicators of Compromise
- Unexpected or repeated reboots of ArmorStart® LT motor controllers
- Link State Monitor down events lasting several seconds
- Anomalous EtherNet/IP traffic patterns targeting ArmorStart® LT devices
- CIP protocol errors or malformed packet logs on network monitoring systems
Detection Strategies
- Monitor network traffic for unusual EtherNet/IP protocol patterns targeting port 44818
- Implement alerting on ArmorStart® LT device reboot events
- Deploy industrial protocol deep packet inspection to identify malformed CIP messages
- Configure SIEM rules to correlate multiple device restart events
Monitoring Recommendations
- Enable logging on network firewalls for EtherNet/IP traffic to ArmorStart® LT devices
- Implement uptime monitoring for all ArmorStart® LT controllers in the environment
- Deploy network-based intrusion detection signatures for known EtherNet/IP attack patterns
- Monitor for Link State Monitor status changes across industrial control systems
How to Mitigate CVE-2025-9466
Immediate Actions Required
- Restrict network access to ArmorStart® LT devices using network segmentation
- Implement firewall rules to limit EtherNet/IP traffic to trusted sources only
- Review and apply any firmware updates from Rockwell Automation
- Enable network monitoring to detect exploitation attempts
Patch Information
Rockwell Automation has published a security advisory (SD1768) addressing this vulnerability. Organizations should consult the Rockwell Automation Security Advisory for specific patch information, firmware updates, and remediation guidance for affected ArmorStart® LT devices.
Workarounds
- Isolate ArmorStart® LT devices on a dedicated network segment with strict access controls
- Implement industrial firewall or ICS-aware security appliances between IT and OT networks
- Disable unnecessary network services and protocols on affected devices where possible
- Deploy network access control lists (ACLs) to restrict EtherNet/IP communication to authorized systems only
# Example firewall rule to restrict EtherNet/IP access (adjust IP ranges as needed)
# Allow EtherNet/IP only from trusted engineering workstations
iptables -A INPUT -p tcp --dport 44818 -s 192.168.100.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 44818 -s 192.168.100.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 44818 -j DROP
iptables -A INPUT -p udp --dport 44818 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
