CVE-2025-9464: ArmorStart LT DoS Vulnerability

CVE-2025-9464 Overview

A denial-of-service vulnerability exists within Rockwell Automation ArmorStart® LT motor controllers. This security issue is triggered during fuzzing of multiple CIP (Common Industrial Protocol) classes, which causes the CIP port to become unresponsive. The vulnerability, classified as CWE-400 (Uncontrolled Resource Consumption), allows remote unauthenticated attackers to disrupt industrial control system operations over the network.

Critical Impact

Remote attackers can render ArmorStart® LT devices unresponsive by exploiting improper handling of CIP class requests, potentially disrupting critical industrial motor control operations.

Affected Products

• Rockwell Automation ArmorStart® LT Motor Controllers
• Industrial control systems utilizing CIP protocol communications
• Devices accessible via network-connected CIP ports

Discovery Timeline

• 2026-01-20 - CVE CVE-2025-9464 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2025-9464

Vulnerability Analysis

This denial-of-service vulnerability stems from improper resource consumption handling within the ArmorStart® LT's CIP protocol implementation. When multiple CIP classes are fuzzed with malformed or excessive requests, the device fails to properly manage resources, causing the CIP port to become completely unresponsive. The attack can be executed remotely over the network without requiring any authentication or user interaction.

The vulnerability poses significant risk to industrial environments where ArmorStart® LT devices control motor operations. Loss of CIP port responsiveness could result in inability to monitor or control connected motors, potentially affecting manufacturing processes, safety systems, or other critical industrial operations.

Root Cause

The root cause is classified as CWE-400: Uncontrolled Resource Consumption. The ArmorStart® LT firmware fails to implement adequate rate limiting, input validation, or resource management when processing CIP class requests. When the device receives a high volume of crafted CIP requests targeting multiple classes simultaneously, it exhausts available resources and enters an unresponsive state.

Attack Vector

The attack is network-based and requires no privileges or user interaction. An attacker with network access to the ArmorStart® LT device can send specially crafted CIP protocol messages targeting multiple CIP classes. The fuzzing activity overwhelms the device's ability to process requests, resulting in the CIP communication port becoming unresponsive.

The attack leverages the CIP protocol's class-based object model, where multiple simultaneous malformed requests to various CIP classes cause resource exhaustion. This can be achieved using standard industrial protocol fuzzing tools or custom scripts targeting CIP endpoints.

Detection Methods for CVE-2025-9464

Indicators of Compromise

• Unusual spike in CIP protocol traffic directed at ArmorStart® LT devices
• CIP port becoming unresponsive on affected motor controllers
• Multiple rapid requests targeting various CIP classes from a single source
• Device communication failures or timeouts in SCADA/HMI systems

Detection Strategies

• Monitor network traffic for abnormal CIP protocol patterns, particularly high-volume requests to multiple CIP classes
• Implement industrial intrusion detection systems (IDS) with CIP protocol inspection capabilities
• Configure SCADA systems to alert on ArmorStart® LT communication failures
• Deploy network anomaly detection to identify fuzzing-like traffic patterns

Monitoring Recommendations

• Establish baseline CIP traffic patterns for ArmorStart® LT devices and alert on deviations
• Monitor device health status and responsiveness through industrial monitoring platforms
• Log all CIP class access attempts for forensic analysis
• Implement network segmentation monitoring to detect unauthorized access to industrial control networks

How to Mitigate CVE-2025-9464

Immediate Actions Required

• Review and restrict network access to ArmorStart® LT devices using firewall rules and network segmentation
• Implement defense-in-depth strategies by placing industrial controllers behind industrial DMZ architectures
• Monitor the Rockwell Automation Security Advisory for firmware updates and patches
• Enable logging and alerting for CIP communication anomalies

Patch Information

Organizations should consult the official Rockwell Automation Security Advisory SD1768 for the latest patch information and firmware updates. As of the publication date, affected users should verify the availability of security updates through Rockwell Automation's support channels and apply patches according to their change management procedures.

Workarounds

• Implement strict network segmentation to isolate ArmorStart® LT devices from untrusted networks
• Configure industrial firewalls to filter and rate-limit CIP traffic to affected devices
• Restrict CIP port access to only authorized engineering workstations and control systems
• Deploy industrial-grade intrusion prevention systems (IPS) capable of detecting and blocking CIP protocol abuse

# Example firewall rule to restrict CIP access (port 44818) - adapt to your environment
# Allow only authorized SCADA/HMI systems to communicate with ArmorStart devices
iptables -A INPUT -p tcp --dport 44818 -s 10.0.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 44818 -j DROP
iptables -A INPUT -p udp --dport 44818 -s 10.0.1.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 44818 -j DROP