CVE-2018-17889 in PI Studio HMI
Summary
by MITRE
In WECON Technology Co., Ltd. PI Studio HMI versions 4.1.9 and prior and PI Studio versions 4.2.34 and prior when parsing project files, the XMLParser that ships with Wecon PIStudio is vulnerable to a XML external entity injection attack, which may allow sensitive information disclosure.
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Analysis
by VulDB Data Team • 03/31/2020
The vulnerability CVE-2018-17889 represents a critical XML external entity injection flaw in WECON Technology Co., Ltd. PI Studio HMI and PI Studio software versions 4.1.9 and earlier, as well as PI Studio versions 4.2.34 and earlier. This vulnerability exists within the XML parser component that is bundled with these industrial automation tools, specifically during the processing of project files. The flaw stems from inadequate input validation and sanitization of XML data, allowing malicious actors to manipulate the parsing behavior through crafted external entity references. Such vulnerabilities are particularly dangerous in industrial control systems where these tools are commonly deployed for human machine interface management and process control visualization.
The technical exploitation of this vulnerability occurs when the XML parser encounters external entity declarations within project files that are processed by the software. When these malformed XML documents are parsed, the parser attempts to resolve external entity references, potentially leading to unauthorized data access, information disclosure, or even remote code execution depending on the system configuration. The vulnerability directly maps to CWE-611, which describes improper restriction of XML external entity reference, and aligns with ATT&CK technique T1059.007 for XML external entity injection. This flaw allows attackers to potentially access sensitive system information, configuration data, or other confidential resources that may be referenced through the external entity declarations.
The operational impact of this vulnerability extends beyond simple information disclosure, as it can compromise the integrity and confidentiality of industrial control systems where PI Studio is deployed. In manufacturing environments, this could lead to exposure of proprietary process data, system configurations, or operational parameters that could be exploited by adversaries to disrupt operations or gain deeper access to industrial networks. The vulnerability affects the core functionality of the software, as it impacts the ability to safely process project files, potentially leading to system instability or unauthorized access to critical infrastructure data. Organizations using these versions of PI Studio should be particularly concerned about potential supply chain attacks or insider threats that could leverage this weakness.
Mitigation strategies for this vulnerability include immediate software updates and patches provided by WECON Technology Co., Ltd. to address the XML parser implementation. Organizations should also implement strict file validation and sanitization procedures for all project files before importing them into the system, particularly in environments where untrusted files may be processed. Network segmentation and access controls should be enforced to limit exposure of affected systems, while monitoring should be implemented to detect anomalous XML parsing behavior. The vulnerability highlights the importance of secure coding practices in industrial software development, particularly regarding XML processing and input validation, and underscores the need for regular security assessments of industrial control system components to prevent similar issues in the future.