CVE-2016-4785 in EN100 Ethernet Module
Summary
by MITRE
The integrated web server in the EN100 Ethernet module before 4.27 on Siemens SIPROTEC 4 and SIPROTEC Compact devices allows remote attackers to obtain sensitive information from device memory via an HTTP request.
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Analysis
by VulDB Data Team • 08/22/2022
The vulnerability identified as CVE-2016-4785 affects the EN100 Ethernet module in Siemens SIPROTEC 4 and SIPROTEC Compact protective relays, representing a critical information disclosure flaw that undermines the security posture of industrial control systems. This vulnerability exists within the integrated web server component that is part of the device's network communication infrastructure, specifically impacting devices running firmware versions prior to 4.27. The affected systems operate within critical infrastructure environments where unauthorized access to sensitive operational data could lead to significant operational disruptions and security breaches.
The technical implementation of this vulnerability stems from inadequate input validation and memory handling within the web server's response processing mechanism. When remote attackers send specifically crafted HTTP requests to the affected devices, the web server fails to properly sanitize or restrict memory access, allowing malicious actors to retrieve arbitrary data from the device's memory space. This flaw operates at the application layer of the network stack and leverages the device's legitimate HTTP service to gain unauthorized access to sensitive information that should remain protected within the system's memory boundaries. The vulnerability aligns with CWE-200, which categorizes information exposure issues, and demonstrates how improper access control mechanisms can lead to data leakage in industrial environments.
The operational impact of this vulnerability extends beyond simple information disclosure, as the retrieved memory contents may contain sensitive configuration parameters, authentication credentials, operational settings, or system diagnostics that could be exploited to compromise the entire industrial control system. Attackers could potentially use the leaked information to conduct further attacks such as privilege escalation, system compromise, or targeted attacks against other connected devices within the same network segment. This vulnerability particularly affects critical infrastructure sectors including power generation, water treatment, and manufacturing facilities where Siemens SIPROTEC devices are commonly deployed, making the potential impact of exploitation severe and far-reaching.
Mitigation strategies for CVE-2016-4785 primarily focus on immediate firmware updates to version 4.27 or later, which contain patches addressing the memory access control issues within the web server component. Organizations should also implement network segmentation and access control measures to limit exposure of these devices to untrusted networks, utilizing firewalls and network access control lists to restrict HTTP traffic to only authorized administrative systems. Additionally, regular security assessments and vulnerability scanning should be conducted to identify other potentially affected devices within the industrial control system environment, while monitoring for suspicious network traffic patterns that may indicate exploitation attempts. The vulnerability demonstrates the importance of maintaining up-to-date firmware in industrial environments and aligns with ATT&CK technique T1083, which addresses system information discovery through unauthorized access to system files and memory contents.