CVE-2017-14472 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: Any Description: Requests a specific set of bytes from an undocumented data file and returns the ASCII version of the master password.
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Analysis
by VulDB Data Team • 02/27/2023
The CVE-2017-14472 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 resides in the data, program, and function file permissions functionality, creating a pathway for unauthorized system compromise through unauthenticated network communications. The vulnerability specifically targets the undocumented data file access mechanism that handles master password retrieval, making it particularly dangerous as it bypasses normal authentication procedures and exposes core system credentials.
The technical implementation of this vulnerability exploits a flaw in how the device processes incoming packets, particularly those requesting specific byte sequences from internal data files. When an attacker sends a specially crafted packet, the system performs a read operation that inadvertently returns the ASCII representation of the master password stored in an undocumented data file. This occurs regardless of the keyswitch state, which can be in any position including RUN, PROG, or REMOTE modes, effectively removing any physical security barriers. The vulnerability operates at the network protocol level, utilizing the Modbus protocol stack that is commonly used for industrial control systems communication.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it provides attackers with complete administrative access to the programmable logic controller. Once the master password is obtained, adversaries can modify system settings, alter ladder logic programs, and potentially manipulate industrial processes in real-time. This capability enables attackers to conduct sophisticated attacks such as process disruption, data manipulation, or even physical damage to manufacturing equipment. The vulnerability creates a persistent backdoor that can be exploited repeatedly without requiring additional authentication mechanisms, making it particularly attractive for long-term surveillance or sabotage operations.
From a cybersecurity perspective, this vulnerability aligns with CWE-284 (Improper Access Control) and represents a classic example of insufficient authorization checks in industrial control systems. The flaw demonstrates the critical importance of secure by design principles in industrial environments where network accessibility is often required for maintenance and monitoring purposes. Organizations implementing the affected Allen Bradley devices should consider this vulnerability in their threat modeling exercises and align their mitigation strategies with the ATT&CK framework's industrial control systems tactics, particularly those related to privilege escalation and defense evasion. The vulnerability also highlights the need for proper network segmentation and access controls in industrial environments, as the attack can be executed from any location that can reach the device over the network.
Mitigation strategies should focus on immediate firmware updates to versions that address the access control flaw, network segmentation to isolate affected devices from general corporate networks, and implementation of network access controls using firewalls or network access control lists. Additionally, organizations should conduct thorough vulnerability assessments of their industrial control systems to identify similar undocumented access mechanisms that may pose similar risks. The vulnerability underscores the importance of maintaining current firmware versions and implementing proper network monitoring to detect anomalous packet patterns that may indicate exploitation attempts. Regular security audits of industrial control systems should include assessment of undocumented functionality and access control mechanisms to prevent similar vulnerabilities from remaining undetected in operational environments.