CVE-2025-13824 is a vulnerability classified under CWE-763 (Release of Invalid Pointer or Reference) affecting Rockwell Automation's Micro820®, Micro850®, and Micro870® programmable logic controllers (PLCs). The flaw stems from improper handling of malformed Common Industrial Protocol (CIP) packets during fuzzing activities. When such malformed packets are received, the controller experiences a hard fault, indicated by a solid red Fault LED, rendering the device unresponsive. Upon power cycling, the device transitions into a recoverable fault state, where both the MS LED and Fault LED flash red and the controller reports fault code 0xF019. Recovery requires manual clearing of the fault condition. The vulnerability has a CVSS 4.0 base score of 8.7, reflecting high severity due to its network attack vector (AV:N), low attack complexity (AC:L), and no requirement for authentication or user interaction. The impact is primarily a denial-of-service (DoS) condition that disrupts controller availability, potentially halting industrial processes controlled by these devices. No patches or firmware updates are currently linked, and no known exploits have been reported in the wild. The vulnerability highlights risks in industrial control systems (ICS) where malformed network traffic can cause critical hardware faults, emphasizing the need for robust input validation and network security controls in ICS environments.

The primary impact of CVE-2025-13824 is a denial-of-service condition on Rockwell Automation Micro820®, Micro850®, and Micro870® controllers, which are widely used in industrial automation and critical infrastructure sectors. For European organizations, this can translate into operational disruptions in manufacturing plants, utilities, and process control environments, potentially causing production downtime and safety risks. The fault state requires manual intervention to clear, increasing operational costs and downtime. Given the controllers' role in automation, prolonged unavailability could impact supply chains and critical services. The lack of authentication or user interaction for exploitation means attackers can remotely induce faults if they gain network access, increasing the threat surface. Although no known exploits exist yet, the vulnerability's high CVSS score and ease of exploitation make it a significant risk for European industrial operators relying on these devices.

1. Monitor Rockwell Automation's advisories closely for firmware updates or patches addressing CVE-2025-13824 and apply them promptly once available. 2. Implement strict network segmentation and access controls to isolate industrial control networks from general IT networks and the internet, minimizing exposure to malformed CIP packets. 3. Deploy intrusion detection/prevention systems (IDS/IPS) capable of identifying and blocking malformed CIP traffic patterns to prevent exploitation attempts. 4. Conduct regular network traffic analysis to detect anomalies or fuzzing attempts targeting CIP protocols. 5. Establish incident response procedures for rapid fault clearing and recovery to minimize downtime if exploitation occurs. 6. Train operational technology (OT) personnel to recognize fault indicators such as the red Fault LED and fault code 0xF019 for timely response. 7. Limit network access to trusted devices and users only, using strong authentication and encryption where possible to reduce attack vectors. 8. Consider implementing CIP protocol filtering or validation at network boundaries to reject malformed packets before reaching controllers.