CVE-2014-5410 in Ab Micrologix Controller
Summary
by MITRE
The DNP3 feature on Rockwell Automation Allen-Bradley MicroLogix 1400 1766-Lxxxxx A FRN controllers 7 and earlier and 1400 1766-Lxxxxx B FRN controllers before 15.001 allows remote attackers to cause a denial of service (process disruption) via malformed packets over (1) an Ethernet network or (2) a serial line.
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Analysis
by VulDB Data Team • 11/05/2025
The vulnerability identified as CVE-2014-5410 affects Rockwell Automation Allen-Bradley MicroLogix 1400 controllers running specific firmware versions, presenting a critical remote denial of service risk within industrial control systems. This flaw resides in the DNP3 protocol implementation used for communication between these controllers and supervisory systems, making it particularly dangerous in environments where continuous operation is essential for safety and production processes. The affected controllers operate with firmware versions 7 and earlier for the A FRN series and before 15.001 for the B FRN series, representing a significant portion of legacy industrial equipment still operational in manufacturing and critical infrastructure sectors.
The technical flaw manifests through improper handling of malformed packets within the DNP3 communication layer, which operates over both Ethernet networks and serial line connections. When remote attackers send specially crafted malformed packets to these controllers, the system fails to properly validate incoming data structures, leading to process disruption and complete system unavailability. This vulnerability directly maps to CWE-129, Input Validation, and CWE-400, Uncontrolled Resource Consumption, as the controller's response to malformed packets consumes excessive resources or triggers unexpected behavior patterns. The DNP3 protocol, designed for reliable communication in industrial environments, becomes a vector for exploitation when the receiving end lacks proper packet validation mechanisms.
The operational impact of this vulnerability extends beyond simple service disruption, as it can compromise entire production lines and industrial processes that depend on these controllers for critical functions. In manufacturing environments, a denial of service attack on a MicroLogix 1400 controller can halt production lines, disrupt quality control systems, and potentially lead to safety hazards in facilities where process control is paramount. The remote nature of the attack means that threat actors can exploit this vulnerability from outside the facility's network perimeter, making traditional network security measures insufficient for protection. This vulnerability aligns with ATT&CK technique T1499.001, Network Denial of Service, and demonstrates how industrial control systems remain vulnerable to attacks that leverage protocol implementation flaws rather than cryptographic weaknesses.
Mitigation strategies for this vulnerability require immediate firmware updates from Rockwell Automation, as the company has released patches addressing the DNP3 packet validation issues. Organizations should implement network segmentation to isolate these controllers from general network traffic, deploy intrusion detection systems specifically configured to monitor DNP3 protocol traffic, and establish network access controls to limit communication to authorized endpoints only. Additionally, implementing serial line security measures such as physical access controls and monitoring for unauthorized serial connections can help reduce attack surface. The vulnerability highlights the importance of maintaining current firmware versions and conducting regular security assessments of industrial control systems, as legacy equipment often lacks the security features present in modern industrial protocols. Organizations should also consider implementing redundant control systems and emergency shutdown procedures to minimize operational impact during potential exploitation attempts.