CVE-2016-8380 in ILC PLC
Summary
by MITRE
The web server in Phoenix Contact ILC PLCs allows access to read and write PLC variables without authentication.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 05/29/2025
The vulnerability identified as CVE-2016-8380 affects Phoenix Contact ILC programmable logic controllers where the embedded web server implementation lacks proper authentication mechanisms for accessing programmable logic controller variables. This represents a critical security flaw that fundamentally undermines the integrity and confidentiality of industrial control systems. The affected devices operate within industrial environments where operational technology (OT) systems require robust security controls to prevent unauthorized access to critical infrastructure components. The absence of authentication checks creates an attack surface that allows any remote user to manipulate PLC variables directly through the web interface, potentially leading to system compromise and operational disruption.
This vulnerability stems from a fundamental flaw in the web server implementation where the security model fails to enforce access controls for variable manipulation functions. The technical nature of the flaw aligns with CWE-284, which describes improper access control in software systems, and specifically manifests as a lack of authentication mechanisms for sensitive operations. The vulnerability exists at the application layer of the industrial control system architecture, where the web server component fails to validate user credentials before allowing read and write operations on PLC variables. This weakness enables attackers to bypass normal security protocols and directly interact with the controller's memory space through unauthenticated HTTP requests.
The operational impact of this vulnerability extends beyond simple unauthorized access, creating potential for significant industrial control system compromise. Attackers could manipulate PLC variables to alter control logic, change process parameters, or disable safety mechanisms, potentially leading to equipment damage, production downtime, or hazardous conditions. The vulnerability affects the availability, integrity, and confidentiality of industrial processes, as unauthorized users can modify critical control parameters without detection. This represents a severe risk in environments where PLCs control critical infrastructure such as manufacturing processes, power generation, or water treatment facilities, where unauthorized modifications could result in cascading failures or safety incidents.
Organizations should implement immediate mitigations including network segmentation to isolate affected PLCs from general network access, deployment of network access control measures to restrict web server access, and application of firmware updates from Phoenix Contact when available. The implementation of network firewalls and access control lists should be enforced to limit access to the web server interface to authorized personnel only. Additionally, organizations should conduct comprehensive vulnerability assessments of their industrial control systems to identify similar authentication weaknesses in other devices. This vulnerability demonstrates the importance of applying the principle of least privilege in OT environments and highlights the need for regular security assessments of industrial systems, as outlined in the NIST Cybersecurity Framework and ISO 27001 standards for industrial security management.