CVE-2017-14465 in MicroLogix 1400
Summary
by MITRE
An exploitable access control vulnerability exists in the data, program, and function file permissions functionality of Allen Bradley Micrologix 1400 Series B FRN 21.2 and before. A specially crafted packet can cause a read or write operation resulting in disclosure of sensitive information, modification of settings, or modification of ladder logic. An attacker can send unauthenticated packets to trigger this vulnerability. Required Keyswitch State: REMOTE Description: Any input or output can be forced, causing unpredictable activity from the PLC.
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Analysis
by VulDB Data Team • 02/27/2023
The CVE-2017-14465 vulnerability represents a critical access control flaw within Allen Bradley Micrologix 1400 Series Programmable Logic Controllers running firmware version 21.2 and earlier. This weakness specifically targets the data, program, and function file permissions mechanisms that govern how the PLC manages its internal resources and controls access to its operational parameters. The vulnerability exists in the communication protocols that handle file access operations, creating a pathway for unauthorized manipulation of the controller's core functions. The affected devices operate under a REMOTE keyswitch state, which is a critical operational context where the PLC is configured for remote operation but lacks proper authentication mechanisms to verify the legitimacy of incoming requests. This creates a dangerous scenario where any attacker with network access can exploit the vulnerability without requiring authentication credentials, fundamentally undermining the security posture of industrial control systems.
The technical exploitation of this vulnerability occurs through the manipulation of specially crafted network packets that target the PLC's file permission handling subsystem. When these malformed packets are transmitted to the controller, they trigger unauthorized read or write operations against critical system files including ladder logic programs, data files, and function definitions. The vulnerability allows attackers to force any input or output within the PLC, which can lead to unpredictable behavior and potentially dangerous operational states. This capability enables threat actors to modify the controller's operational parameters, access sensitive configuration data, or alter the programmable logic that governs industrial processes. The flaw essentially bypasses the normal access control checks that should prevent unauthorized modifications to the controller's core operational components, creating a persistent threat vector for industrial espionage and operational disruption.
The operational impact of CVE-2017-14465 extends far beyond simple data disclosure, as it provides attackers with the ability to fundamentally alter the behavior of industrial control systems. When an attacker can force inputs and outputs, they gain the capability to manipulate physical processes in real-time, potentially causing equipment damage, safety hazards, or production disruptions. The ability to modify ladder logic programs means that attackers can change the operational sequences of industrial processes, leading to unsafe operating conditions or complete system failures. This vulnerability particularly affects manufacturing environments where PLCs control critical machinery, assembly lines, or process control systems, making it a significant concern for industrial security. The remote exploitation capability means that attackers do not need physical access to the facility, allowing them to target systems from anywhere on the network, which increases the attack surface and makes the vulnerability particularly dangerous in connected industrial environments.
Organizations must implement multiple layers of defense to protect against this vulnerability, beginning with immediate firmware updates to versions that address the access control flaw. Network segmentation should be implemented to isolate PLCs from general corporate networks, and strict access controls should be enforced using firewalls and network access control lists. The implementation of network monitoring solutions that can detect anomalous packet patterns and unauthorized access attempts provides additional protection. Security assessments should include specific testing for this vulnerability using industrial protocol analyzers and penetration testing tools designed for industrial control systems. Regular security audits of industrial networks should be conducted to identify and remediate similar access control weaknesses in other PLC models and industrial devices. According to CWE standards, this vulnerability maps to CWE-284 Access Control Issues, specifically related to inadequate permissions checking in industrial control systems. The ATT&CK framework categorizes this vulnerability under T1071.001 Application Layer Protocol: Web Protocols, as it involves exploitation of network protocols used for industrial control communications, and T1059 Command and Scripting Interpreter, since successful exploitation may involve executing commands through the PLC interface. The vulnerability demonstrates the critical need for robust industrial cybersecurity practices that consider both the unique operational requirements of industrial environments and the evolving threat landscape targeting critical infrastructure systems.