CVE-2017-7689 in homeLYnk
Summary
by MITRE
A Command Injection vulnerability in Schneider Electric homeLYnk Controller exists in all versions before 1.5.0.
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Analysis
by VulDB Data Team • 04/12/2017
The CVE-2017-7689 vulnerability represents a critical command injection flaw within Schneider Electric's homeLYnk Controller device, affecting all software versions prior to 1.5.0. This vulnerability resides in the device's web interface handling mechanism where user-supplied input is inadequately sanitized before being processed by the underlying operating system. The flaw allows an attacker to execute arbitrary commands on the device with the privileges of the web server process, potentially leading to complete system compromise. The vulnerability stems from improper input validation and output encoding practices within the controller's web application framework, creating an avenue for malicious actors to inject command sequences that bypass normal security controls. The homeLYnk Controller serves as a central hub for home automation systems, managing various connected devices and protocols, making this vulnerability particularly dangerous as it could enable attackers to gain unauthorized access to entire home networks.
The technical exploitation of this command injection vulnerability occurs when an attacker submits malicious input through web interface parameters or form fields that are subsequently passed to system commands without proper sanitization. This flaw typically manifests in scenarios where the application constructs shell commands by concatenating user input directly into command strings, rather than using parameterized approaches or proper input validation. The vulnerability is classified under CWE-77 as Command Injection, which is a well-documented weakness in software applications where untrusted data is incorporated into system command invocations. Attackers can leverage this vulnerability to execute arbitrary code on the device, potentially gaining access to sensitive configuration data, network credentials, or even escalating privileges to root-level access. The impact is amplified by the fact that the homeLYnk Controller operates within residential environments where network security may be less robust compared to enterprise settings, making it an attractive target for cybercriminals seeking to establish persistent access points.
The operational impact of CVE-2017-7689 extends beyond simple system compromise to encompass potential widespread network infiltration and data breaches within home automation ecosystems. Once an attacker successfully exploits this vulnerability, they can manipulate the controller's functionality to redirect network traffic, modify device configurations, or establish backdoor access for future exploitation. The compromised device can serve as a launching point for lateral movement attacks within the home network, potentially compromising other connected IoT devices such as smart thermostats, security cameras, or connected appliances. This vulnerability directly aligns with ATT&CK technique T1059.001 for Command and Scripting Interpreter, where adversaries use legitimate system utilities to execute malicious commands. The attack surface is particularly concerning given that home automation controllers often contain sensitive personal data including user preferences, access schedules, and network configuration details that could be exploited for identity theft or further targeted attacks. Additionally, the compromised device could be used to conduct distributed denial-of-service attacks or to mine cryptocurrency, depending on the attacker's objectives.
Mitigation strategies for CVE-2017-7689 primarily focus on immediate software updates and robust input validation implementations. Organizations and individuals should prioritize upgrading to Schneider Electric's patched version 1.5.0 or later, which incorporates proper input sanitization and command execution controls. Network segmentation practices should be implemented to isolate home automation controllers from critical network segments, reducing the potential impact of successful exploitation. The implementation of web application firewalls and input validation rules can provide additional protection layers against command injection attempts. Security monitoring should be enhanced to detect anomalous command execution patterns or unusual network behavior originating from the controller. Access controls should be strengthened through multi-factor authentication and role-based permissions to limit the attack surface. System administrators should conduct regular security audits of home automation devices and maintain updated vulnerability assessments to identify similar weaknesses in other networked devices. The remediation process should also include network traffic analysis to detect potential exploitation attempts and ensure that the patched software is properly installed and functioning as intended. Given the nature of the vulnerability, comprehensive security training for users on recognizing potential attack vectors and maintaining secure device configurations is essential for long-term protection against similar threats.