CVE-2016-8366 in ILC PLC
Summary
by MITRE
Webvisit in Phoenix Contact ILC PLCs offers a password macro to protect HMI pages on the PLC against casual or coincidental opening of HMI pages by the user. The password macro can be configured in a way that the password is stored and transferred in clear text.
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Analysis
by VulDB Data Team • 07/29/2024
The vulnerability identified as CVE-2016-8366 affects Webvisit functionality within Phoenix Contact ILC PLCs, representing a significant security weakness in industrial control systems. This flaw resides in the password protection mechanism designed to safeguard HMI pages from unauthorized access, creating a critical exposure in industrial environments where operational technology security is paramount. The vulnerability stems from the configuration option that allows passwords to be stored and transmitted in clear text format, fundamentally undermining the security controls intended to protect sensitive operational interfaces. This design flaw directly violates established security principles for protecting authentication credentials in industrial settings.
The technical implementation of this vulnerability demonstrates a failure in cryptographic security practices where sensitive authentication data is not properly encrypted during storage or transmission phases. When administrators configure the password macro, they can inadvertently enable clear text storage and transfer of passwords, creating an attack surface that allows unauthorized parties to intercept and access protected HMI pages. This weakness operates at the application layer of the industrial control system architecture, specifically affecting the communication protocols used by the Webvisit interface to authenticate users accessing human machine interfaces. The vulnerability is classified under CWE-312, which addresses the exposure of sensitive information through cleartext storage or transmission, making it particularly dangerous in industrial environments where such systems control critical infrastructure operations.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential disruption of industrial processes and compromise of operational integrity. Attackers who exploit this weakness can gain access to HMI pages containing critical operational parameters, system configurations, and control functions without requiring additional authentication mechanisms. This access could enable malicious actors to manipulate system settings, monitor operational data, or potentially cause operational disruptions that affect production processes. The vulnerability particularly affects environments where industrial systems are connected to corporate networks or the internet, as clear text credentials become easily accessible to attackers during network transmission or storage phases. The risk is compounded by the fact that this vulnerability exists within the core authentication mechanism of the PLC's user interface, potentially allowing attackers to gain unauthorized access to critical operational controls.
Organizations should implement immediate mitigations including disabling the clear text password storage configuration option, implementing network segmentation to isolate PLCs from general network access, and conducting comprehensive security assessments of all industrial control systems. The implementation of encrypted communication protocols and secure authentication mechanisms should be prioritized to address the root cause of this vulnerability. Additionally, regular security audits and penetration testing of industrial control systems should be conducted to identify similar configuration weaknesses. This vulnerability aligns with ATT&CK technique T1078 which covers valid accounts and credential access, demonstrating how insecure password handling can provide attackers with unauthorized access to critical systems. The remediation efforts should also include staff training on secure configuration practices for industrial control systems, as this vulnerability often results from configuration errors rather than deliberate design flaws.