CVE-2020-5609 in CENTUM CS 3000
Summary
by MITRE
Directory traversal vulnerability in CAMS for HIS CENTUM CS 3000 (includes CENTUM CS 3000 Small) R3.08.10 to R3.09.50, CENTUM VP (includes CENTUM VP Small, Basic) R4.01.00 to R6.07.00, B/M9000CS R5.04.01 to R5.05.01, and B/M9000 VP R6.01.01 to R8.03.01 allows a remote unauthenticated attacker to create or overwrite arbitrary files and run arbitrary commands via unspecified vectors.
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Analysis
by VulDB Data Team • 08/05/2020
The CVE-2020-5609 vulnerability represents a critical directory traversal flaw affecting multiple Siemens industrial control systems including CAMS for HIS CENTUM CS 3000 series, CENTUM VP systems, and B/M9000 series. This vulnerability exists within software versions ranging from R3.08.10 through R3.09.50 for CENTUM CS 3000, R4.01.00 to R6.07.00 for CENTUM VP, and various releases of B/M9000CS and B/M9000 VP systems. The flaw stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing file system operations, creating a pathway for malicious actors to manipulate file paths and execute unauthorized operations.
The technical implementation of this vulnerability allows remote unauthenticated attackers to exploit the directory traversal condition through unspecified vectors within the affected systems. When the vulnerable software processes user input containing directory traversal sequences such as ../ or ..\, it fails to validate or sanitize these inputs properly, enabling attackers to manipulate file system operations. This weakness directly maps to CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which is a fundamental security flaw in path validation and access control mechanisms. The vulnerability enables attackers to create or overwrite arbitrary files within the system's file structure, potentially leading to complete system compromise and unauthorized code execution.
The operational impact of CVE-2020-5609 extends beyond simple file manipulation to encompass full system compromise and potential operational technology disruption. Attackers can leverage this vulnerability to execute arbitrary commands on affected systems, potentially gaining persistent access to critical industrial control environments. The remote unauthenticated nature of the attack means that adversaries can exploit this vulnerability without requiring legitimate credentials, making it particularly dangerous in operational technology environments where security controls may be less stringent than in traditional IT environments. This vulnerability directly aligns with ATT&CK technique T1059 - Command and Scripting Interpreter, where attackers can execute malicious commands through compromised systems. The implications are severe for industrial control systems where such compromises could lead to production disruptions, safety hazards, or unauthorized access to critical infrastructure operations.
Organizations operating affected Siemens systems should implement immediate mitigations including network segmentation to restrict access to these systems, deployment of network firewalls to block unauthorized access attempts, and implementation of intrusion detection systems to monitor for exploitation attempts. The most effective long-term solution involves applying official patches and updates provided by Siemens to address the directory traversal vulnerability in affected software versions. System administrators should conduct comprehensive vulnerability assessments to identify all instances of the affected software and ensure proper access controls are implemented. Additionally, implementing principle of least privilege access controls, regular security monitoring, and maintaining updated security baselines can help reduce the attack surface and mitigate the risk of exploitation. Organizations should also consider implementing network access controls to limit remote access to these critical systems, particularly in environments where such access is not strictly required for operational purposes.