CVE-2020-7494 in EcoStruxure Operator Terminal Expert
Summary
by MITRE
A CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability exists in EcoStruxure Operator Terminal Expert 3.1 Service Pack 1 and prior (formerly known as Vijeo XD) which could cause malicious code execution when opening the project file.
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Analysis
by VulDB Data Team • 11/20/2020
The vulnerability identified as CVE-2020-7494 represents a critical path traversal flaw classified under CWE-22 that affects EcoStruxure Operator Terminal Expert 3.1 Service Pack 1 and earlier versions, formerly known as Vijeo XD. This industrial automation software is widely used for configuring and managing operator terminals in industrial control systems, making the vulnerability particularly concerning for operational technology environments. The flaw resides in how the application processes project files, specifically failing to properly validate or sanitize file paths during project loading operations. When a maliciously crafted project file is opened, the software does not adequately restrict pathname access to restricted directories, allowing an attacker to manipulate file paths and potentially access or execute arbitrary code on the system. This vulnerability operates at the intersection of software security and industrial control systems, where the consequences of exploitation could extend beyond traditional information technology risks to impact physical processes and operational safety. The vulnerability's impact is amplified by the fact that it requires no special privileges to exploit, as the malicious project file can be delivered through social engineering or compromised software distribution channels, making it particularly dangerous in industrial environments where operators may unknowingly open compromised files.
The technical mechanism behind this path traversal vulnerability involves the application's failure to implement proper input validation when processing project file contents that contain file path references. Attackers can craft project files that include specially formatted path traversal sequences such as "../" or similar constructs that bypass directory restrictions intended to prevent access to sensitive system locations. When the vulnerable software loads these malicious project files, it processes the embedded paths without adequate sanitization, allowing the execution of code from arbitrary locations on the filesystem. The exploitation requires the victim to open a specially crafted project file, which typically occurs during normal software operation when users load existing projects or import configurations. This vulnerability directly maps to the ATT&CK framework's technique T1059.001 for Command and Scripting Interpreter and T1068 for Exploitation for Privilege Escalation, as successful exploitation can lead to code execution with the privileges of the running process. The flaw is particularly dangerous because it can be exploited through simple file manipulation without requiring complex attack vectors, making it accessible to threat actors with varying skill levels. The vulnerability also aligns with the MITRE ATT&CK framework's focus on software supply chain attacks and the exploitation of industrial control system software, as it represents a weakness in commonly deployed industrial automation tools.
The operational impact of CVE-2020-7494 extends significantly beyond traditional cybersecurity concerns into the realm of industrial control system security and operational technology safety. In industrial environments where EcoStruxure Operator Terminal Expert is deployed, successful exploitation could lead to unauthorized access to critical control system configurations, potentially allowing attackers to manipulate industrial processes, access sensitive operational data, or disrupt production operations. The vulnerability's ability to execute code on the target system creates multiple attack vectors for further compromise, including lateral movement within industrial networks, data exfiltration, or the installation of persistent backdoors. Organizations using this software may face regulatory compliance challenges, as the vulnerability could violate standards such as NIST SP 800-82 for industrial control systems security or IEC 62443 for industrial automation and control systems. The impact is particularly severe in environments where operator terminals are directly connected to or integrated with process control systems, as the compromise of these terminals could potentially lead to physical system manipulation or safety system degradation. Recovery from exploitation could involve complete system reinstallation, configuration validation, and potential operational downtime that could significantly impact industrial operations and safety protocols.
Organizations should implement immediate mitigations including applying the vendor-provided security patches and updates to address CVE-2020-7494. System administrators should implement strict file access controls and privilege separation, ensuring that the software runs with minimal required privileges and that project file access is properly restricted. Network segmentation and file transfer controls should be implemented to prevent unauthorized project file distribution, including email filtering and application whitelisting to prevent execution of untrusted project files. Regular security assessments should be conducted to identify and remediate similar vulnerabilities in other industrial control system software, as this vulnerability demonstrates the need for comprehensive security testing of operational technology environments. Additionally, organizations should establish robust incident response procedures specifically tailored to industrial control system security incidents, including regular testing of backup and recovery procedures to ensure operational continuity in case of successful exploitation. The vulnerability highlights the importance of secure software development practices in industrial environments and the need for continuous security monitoring of operational technology assets. Security teams should also consider implementing file integrity monitoring solutions to detect unauthorized modifications to project files and establish baseline configurations that can be quickly restored in case of compromise, ensuring both system integrity and operational availability.