CVE-2017-5139 in XL Web II
Summary
by MITRE
An issue was discovered in Honeywell XL Web II controller XL1000C500 XLWebExe-2-01-00 and prior, and XLWeb 500 XLWebExe-1-02-08 and prior. Any user is able to disclose a password by accessing a specific URL, because of Plaintext Storage of a Password.
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Analysis
by VulDB Data Team • 08/14/2020
The vulnerability identified as CVE-2017-5139 represents a critical security flaw in Honeywell XL Web II controllers, specifically affecting firmware versions up to XLWebExe-2-01-00 and XLWeb 500 XLWebExe-1-02-08. This issue stems from improper password handling mechanisms within the web interface of these industrial control systems, creating a significant exposure that allows unauthorized access to system credentials. The vulnerability specifically affects the XL1000C500 model and related systems, which are commonly deployed in industrial environments for process control and monitoring. The flaw manifests when users can directly access a specific URL that reveals stored passwords in plaintext format, bypassing normal authentication mechanisms and providing immediate access to system administrative functions.
The technical root cause of this vulnerability aligns with CWE-256, which addresses the storage of passwords in plaintext format, and more specifically with CWE-312, which deals with the exposure of sensitive information through improper data handling. The flaw operates at the application layer where the web interface fails to properly encrypt or obfuscate password storage, leaving credentials accessible through direct URL access. This represents a fundamental failure in secure credential management practices, as the system stores passwords in a format that can be immediately retrieved without requiring authentication or authorization. The vulnerability exists because the web application does not implement proper access controls or encryption mechanisms for sensitive data, allowing any authenticated user to access the password disclosure endpoint.
The operational impact of this vulnerability is severe for industrial control systems that rely on Honeywell XL Web II controllers, as it provides attackers with immediate access to administrative credentials that could be used to modify system configurations, access sensitive operational data, or potentially disrupt industrial processes. The ability to disclose passwords through a simple URL access means that even basic network reconnaissance can reveal critical system credentials, making this vulnerability particularly dangerous in environments where physical security may be compromised or where network access is not properly restricted. Attackers could exploit this vulnerability to gain full administrative control over the affected controllers, potentially leading to unauthorized modifications of process parameters, data manipulation, or complete system compromise that could affect production operations and safety systems.
Organizations affected by this vulnerability should implement immediate mitigations including updating to the latest firmware versions that address the plaintext password storage issue, implementing network segmentation to restrict access to these controllers, and ensuring that administrative access is limited to authorized personnel only. The remediation process should involve verifying that password storage mechanisms properly implement encryption or hashing techniques to prevent plaintext exposure. Additionally, network access controls should be configured to limit access to these specific URLs and web interfaces, while monitoring systems should be implemented to detect unauthorized access attempts. This vulnerability demonstrates the importance of following security best practices in industrial control systems and highlights the need for proper credential management and access control mechanisms to prevent unauthorized access to critical infrastructure components. The issue also underscores the relevance of ATT&CK technique T1566, which involves credential access through exploitation of vulnerabilities in web applications, and emphasizes the need for comprehensive security controls in operational technology environments.