CVE-2020-7491 in TCM
Summary
by MITRE
**VERSION NOT SUPPORTED WHEN ASSIGNED** A legacy debug port account in TCMs installed in Tricon system versions 10.2.0 through 10.5.3 is visible on the network and could allow inappropriate access. This vulnerability was remediated in TCM version 10.5.4.
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Analysis
by VulDB Data Team • 07/24/2020
The vulnerability identified as CVE-2020-7491 represents a critical security flaw in Triconex TCM (Tricon System Controller Module) versions 10.2.0 through 10.5.3 that exposes legacy debug port accounts on the network. This issue specifically affects industrial control systems where operational technology infrastructure requires robust security measures to prevent unauthorized access to critical control systems. The Triconex system operates within industrial environments where safety and security are paramount, making vulnerabilities of this nature particularly concerning for critical infrastructure sectors including manufacturing, oil and gas, and power generation facilities.
The technical flaw stems from the presence of legacy debug accounts that remain active and accessible through network connections even after the system has been deployed in production environments. These accounts, typically intended for debugging purposes during development or initial deployment phases, were not properly disabled or secured in the released versions of the TCM software. The vulnerability allows remote attackers to potentially gain unauthorized access to the system through these exposed accounts, bypassing normal authentication mechanisms that should protect industrial control systems from external threats.
From an operational impact perspective, this vulnerability creates significant risk for organizations utilizing Triconex systems in industrial environments where security is critical. The exposure of debug accounts through network access means that unauthorized parties could potentially gain access to control systems that manage critical processes, potentially leading to system compromise, operational disruption, or even safety hazards in industrial settings. The vulnerability affects multiple versions of the TCM software, indicating it was a persistent issue that required remediation across several releases, highlighting the importance of proper security configuration management in industrial control systems.
The remediation implemented in TCM version 10.5.4 addresses this vulnerability by properly disabling or securing the legacy debug accounts that were previously accessible over the network. This update represents a standard security practice that aligns with industry best practices for securing industrial control systems and follows the principles outlined in the MITRE ATT&CK framework for industrial control systems, specifically addressing techniques related to credential access and remote access. Organizations should prioritize updating to version 10.5.4 or later to ensure proper security posture, as this vulnerability could be exploited by threat actors targeting industrial control systems.
This vulnerability type maps to CWE-259: Use of Hard-coded Password and CWE-798: Use of Hard-coded Credentials, which are fundamental security weaknesses in industrial control systems where hardcoded credentials can provide unauthorized access to critical infrastructure. The issue also relates to the broader category of insecure default configurations that are commonly exploited in industrial environments, emphasizing the need for comprehensive security assessments and proper configuration management throughout the operational lifecycle of industrial control systems. Organizations should implement network segmentation, access controls, and regular security audits to prevent similar vulnerabilities from occurring in their industrial control infrastructure.