CVE-2016-8367 in Magelis
Summary
by MITRE
An issue was discovered in Schneider Electric Magelis HMI Magelis GTO Advanced Optimum Panels, all versions, Magelis GTU Universal Panel, all versions, Magelis STO5xx and STU Small panels, all versions, Magelis XBT GH Advanced Hand-held Panels, all versions, Magelis XBT GK Advanced Touchscreen Panels with Keyboard, all versions, Magelis XBT GT Advanced Touchscreen Panels, all versions, and Magelis XBT GTW Advanced Open Touchscreen Panels (Windows XPe). An attacker can open multiple connections to a targeted web server and keep connections open preventing new connections from being made, rendering the web server unavailable during an attack.
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Analysis
by VulDB Data Team • 09/02/2020
This vulnerability represents a critical denial of service condition affecting multiple Schneider Electric Magelis HMI panel models running Windows XPe operating system. The flaw manifests as a resource exhaustion attack where malicious actors can establish numerous concurrent connections to the web server component of these industrial control panels. The affected devices include advanced Optimum Panels, Universal Panels, Small panels, and various touchscreen handheld models across different product lines. These industrial control systems are commonly deployed in critical infrastructure environments where availability of human machine interfaces is essential for operational continuity. The vulnerability specifically targets the web server functionality that serves as the primary interface for configuration, monitoring, and control operations within these panels.
The technical implementation of this vulnerability exploits the web server's connection handling mechanism without proper rate limiting or connection management controls. When an attacker opens multiple connections and maintains them in an open state, the web server's connection pool becomes saturated and unable to accept new incoming requests. This behavior constitutes a classic resource exhaustion attack pattern that can be classified under CWE-400 as "Uncontrolled Resource Consumption" and specifically relates to CWE-1321 "Improperly Controlled Resource Consumption". The attack does not require authentication or complex exploitation techniques, making it particularly dangerous for industrial environments where physical access may be limited but network access could be compromised. The Windows XPe operating system's web server implementation lacks adequate protection against this specific attack vector, creating a persistent availability risk for operators who rely on these interfaces for critical control functions.
The operational impact of this vulnerability extends beyond simple service disruption to potentially compromise industrial process control and monitoring capabilities. In critical infrastructure environments such as manufacturing plants, water treatment facilities, or energy distribution systems, the unavailability of HMI panels can lead to operational paralysis where operators lose access to real-time process data, configuration options, and control functions. This can result in production downtime, safety risks, and potential regulatory compliance issues. The vulnerability affects devices that are often deployed in remote or hard-to-access locations, making rapid response and recovery more challenging. The attack can be executed remotely over network connections, allowing adversaries to target operational technology infrastructure without requiring physical presence. This represents a significant concern for industrial cybersecurity frameworks and aligns with ATT&CK technique T1499.004 "Endpoint Denial of Service" and T1566.001 "Phishing" as attackers might use this vulnerability as part of broader attack chains targeting industrial control systems.
Organizations should implement immediate mitigations including network segmentation to isolate these devices from general network traffic, implementing connection rate limiting on network devices that interface with these panels, and establishing monitoring for unusual connection patterns that might indicate an ongoing attack. Network administrators should consider deploying intrusion detection systems that can identify and alert on excessive connection attempts to web server endpoints. Device vendors should be contacted to determine if firmware updates or patches are available, though industrial environments may require extended testing periods before deployment. Access controls should be strengthened to limit network exposure of these devices, and regular security assessments should be conducted to identify similar vulnerabilities in other operational technology equipment. The vulnerability highlights the importance of applying security principles to operational technology environments where availability is as critical as confidentiality and integrity, and where traditional network security controls may not be sufficient to protect against resource exhaustion attacks targeting embedded web server implementations.