CVE-2023-27396 in SYSMAC CS1
Summary
by MITRE • 06/19/2023
FINS (Factory Interface Network Service) is a message communication protocol, which is designed to be used in closed FA (Factory Automation) networks, and is used in FA networks composed of OMRON products. Multiple OMRON products that implement FINS protocol contain following security issues -- (1)Plaintext communication, and (2)No authentication required. When FINS messages are intercepted, the contents may be retrieved. When arbitrary FINS messages are injected, any commands may be executed on, or the system information may be retrieved from, the affected device. Affected products and versions are as follows: SYSMAC CS-series CPU Units, all versions, SYSMAC CJ-series CPU Units, all versions, SYSMAC CP-series CPU Units, all versions, SYSMAC NJ-series CPU Units, all versions, SYSMAC NX1P-series CPU Units, all versions, SYSMAC NX102-series CPU Units, all versions, and SYSMAC NX7 Database Connection CPU Units (Ver.1.16 or later)
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Analysis
by VulDB Data Team • 11/17/2025
The CVE-2023-27396 vulnerability represents a critical security flaw in OMRON's FINS protocol implementation across multiple SYSMAC series CPU units, fundamentally compromising the security of industrial automation networks. This vulnerability stems from two primary weaknesses: plaintext communication and lack of authentication requirements within the FINS protocol stack. The FINS protocol operates as a factory interface network service designed specifically for closed factory automation environments, where it facilitates communication between industrial control systems and various automation components. When these systems are deployed in operational technology environments, they become prime targets for attackers seeking to exploit communication vulnerabilities that directly impact industrial control systems.
The technical flaw manifests through the absence of encryption and authentication mechanisms within the FINS protocol implementation, creating an environment where network traffic can be intercepted and manipulated without detection. This vulnerability directly maps to CWE-310, which addresses cryptographic weaknesses, and CWE-306, which covers missing authentication. The plaintext communication aspect means that any sensitive data transmitted through FINS can be easily captured and decoded by unauthorized parties, while the lack of authentication allows malicious actors to inject arbitrary FINS messages into the network. This dual weakness creates a pathway for attackers to execute arbitrary commands on affected devices, retrieve system information, and potentially disrupt critical industrial processes.
From an operational impact perspective, this vulnerability poses severe risks to industrial control systems that rely on OMRON's SYSMAC products across multiple series including CS, CJ, CP, NJ, NX1P, NX102, and NX7 Database Connection units. The implications extend beyond simple data theft to include potential system compromise, process disruption, and even physical safety hazards in environments where automation controls critical manufacturing processes or safety systems. Attackers can leverage this vulnerability to gain unauthorized access to industrial control systems, potentially leading to production halts, quality control issues, or more serious safety incidents. The widespread nature of affected products means that organizations across various industrial sectors may be impacted, from manufacturing plants to process control facilities.
The attack surface for this vulnerability aligns with several MITRE ATT&CK framework techniques including T1046 for network service scanning, T1566 for credential harvesting, and T1071 for application layer protocol usage. Organizations should implement immediate mitigations including network segmentation to isolate affected systems, deployment of network monitoring tools to detect unusual FINS protocol activity, and implementation of secure communication channels where possible. The vulnerability also highlights the importance of secure network design principles and adherence to industrial cybersecurity standards such as IEC 62443 and NIST SP 800-82. Organizations must also consider the broader context of industrial network security and implement comprehensive security postures that address both traditional IT security concerns and the unique requirements of industrial control systems. Given the critical nature of these systems, regular security assessments and vulnerability management processes should be enhanced to specifically address protocol-level vulnerabilities in industrial automation environments.