CVE-2017-5142 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. A user with low privileges is able to open and change the parameters by accessing a specific URL because of Improper Privilege Management.
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Analysis
by VulDB Data Team • 08/14/2020
The vulnerability identified as CVE-2017-5142 affects Honeywell XL Web II controllers, specifically versions XL1000C500 XLWebExe-2-01-00 and earlier, as well as XLWeb 500 XLWebExe-1-02-08 and earlier. This issue represents a critical weakness in access control mechanisms within industrial control systems that are designed to manage and monitor critical infrastructure operations. The flaw stems from improper privilege management, which allows attackers with minimal user credentials to manipulate system parameters through direct web interface access.
The technical implementation of this vulnerability demonstrates a fundamental failure in authentication and authorization controls within the web-based management interface of these industrial controllers. The affected systems expose specific URL endpoints that, when accessed directly, bypass normal user privilege checks and allow low-privileged users to modify critical system parameters. This represents a classic case of insufficient access control validation where the application fails to properly verify user permissions before executing parameter modification functions. The vulnerability is particularly concerning because it operates at the application layer, where web-based interfaces are commonly used for system administration and configuration management.
From an operational perspective, this vulnerability creates significant risks for industrial environments that rely on Honeywell XL Web II controllers for critical process control operations. An attacker exploiting this weakness could potentially alter system parameters such as temperature thresholds, pressure settings, or other operational variables that directly impact safety and process integrity. The implications extend beyond simple configuration changes, as these controllers are often integral to manufacturing processes, building automation systems, and other critical infrastructure where unauthorized parameter modifications could lead to operational disruptions, safety hazards, or even physical damage to equipment. The vulnerability effectively undermines the security model of the system by allowing privilege escalation through direct interface manipulation.
The root cause of this vulnerability aligns with CWE-284, which describes improper access control mechanisms in software systems. This weakness specifically manifests as an insufficient authorization check within the web application layer, where the system fails to validate whether the requesting user has appropriate permissions to perform parameter modification operations. From an adversarial perspective, this vulnerability maps to several ATT&CK techniques including privilege escalation and defense evasion, as attackers can leverage this weakness to gain elevated system control without requiring additional authentication mechanisms. The attack vector is particularly effective because it requires minimal expertise to execute, relying on predictable URL structures and the absence of proper access validation.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation strategies to protect their industrial control systems. The most critical immediate action involves applying the vendor-provided security patches and updates that address the privilege management flaw in the web interface. Network segmentation should be implemented to isolate these controllers from general network access, reducing the attack surface available to potential adversaries. Additionally, implementing web application firewalls and access control lists specifically targeting the vulnerable URL endpoints can provide additional protection layers. Regular security assessments and penetration testing of industrial control systems should be conducted to identify similar privilege management weaknesses in other components of the operational technology infrastructure. The vulnerability underscores the importance of applying security updates promptly and maintaining comprehensive security monitoring for industrial systems that may be exposed to external network access.