CVE-2017-14464 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 or PROG Associated Fault Code: 0001 Fault Type: Non-User Description: A fault state can be triggered by setting the NVRAM/memory module user program mismatch bit (S2:9) when a memory module is NOT installed.
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Analysis
by VulDB Data Team • 02/27/2023
The CVE-2017-14464 vulnerability represents a critical access control flaw in Allen Bradley Micrologix 1400 Series B PLCs running firmware version 21.2 or earlier, exposing systems to unauthorized manipulation of industrial control processes. This vulnerability specifically targets the data, program, and function file permissions functionality, which governs how access is controlled to critical system components including ladder logic programs, configuration settings, and operational parameters. The flaw allows attackers to execute read or write operations without proper authentication, fundamentally undermining the security posture of industrial automation environments where these devices are commonly deployed.
The technical exploitation of this vulnerability occurs through specially crafted network packets that can be transmitted to the affected PLCs, bypassing normal authentication mechanisms that should protect against unauthorized access. This issue is particularly concerning because it operates at the firmware level, where the device's core operational logic resides, and can be triggered from remote locations when the keyswitch is set to either REMOTE or PROG modes. The vulnerability's trigger mechanism involves a specific fault state that can be induced by manipulating the NVRAM/memory module user program mismatch bit S2:9, even when no memory module is physically installed in the device. This condition creates a legitimate fault state that can be leveraged to gain unauthorized access to the system's operational controls and data.
The operational impact of this vulnerability extends beyond simple information disclosure, as it enables complete modification of system settings and ladder logic programs that control industrial processes. An attacker who successfully exploits this vulnerability can potentially alter safety systems, modify production parameters, or even cause physical damage to manufacturing equipment by changing the fundamental control logic that governs industrial operations. The implications are particularly severe in environments where these PLCs control critical infrastructure, such as chemical processing plants, water treatment facilities, or manufacturing lines where unauthorized changes could result in safety hazards, production losses, or environmental damage. The vulnerability essentially allows an attacker to assume complete control over the PLC's operational behavior, making it a significant threat to industrial cybersecurity.
Mitigation strategies for CVE-2017-14464 should prioritize immediate firmware updates from Allen Bradley to address the access control implementation flaws, while also implementing network segmentation and access controls to limit exposure to authorized personnel only. Organizations should conduct comprehensive vulnerability assessments to identify all affected devices within their industrial control systems and establish monitoring protocols for unauthorized access attempts. The vulnerability aligns with CWE-284 Access Control Issues, specifically targeting improper access control mechanisms in industrial control systems, and represents a significant concern under ATT&CK framework's TA0005 Defense Evasion and TA0004 Privilege Escalation tactics. Given the critical nature of industrial control systems, organizations should also implement network-based intrusion detection systems specifically tuned to detect anomalous communication patterns that may indicate exploitation attempts against these devices.