CVE-2017-7296 in Operating System
Summary
by MITRE
An issue was discovered in Contiki Operating System 3.0. A Persistent XSS vulnerability is present in the MQTT/IBM Cloud Config page (aka mqtt.html) of cc26xx-web-demo. The cc26xx-web-demo features a webserver that runs on a constrained device. That particular page allows a user to remotely configure that device's operation by sending HTTP POST requests. The vulnerability consists of improper input sanitisation of the text fields on the MQTT/IBM Cloud config page, allowing for JavaScript code injection.
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Analysis
by VulDB Data Team • 12/25/2020
The CVE-2017-7296 vulnerability represents a critical persistent cross-site scripting flaw within the Contiki Operating System version 3.0, specifically affecting the cc26xx-web-demo web server implementation. This vulnerability exists in the MQTT/IBM Cloud configuration page known as mqtt.html, which serves as a remote management interface for cc26xx-based devices. The Contiki OS is designed for resource-constrained embedded systems, making it particularly prevalent in Internet of Things deployments where devices must operate with minimal computational resources while providing web-based administrative capabilities. The web server component of cc26xx-web-demo creates a persistent threat vector by allowing remote configuration through HTTP POST requests, which inherently requires user input validation to prevent malicious code execution.
The technical flaw stems from inadequate input sanitization mechanisms within the MQTT/IBM Cloud configuration page, where text fields receive user-provided data without proper validation or encoding. This vulnerability directly maps to CWE-79, Cross-site Scripting, with the persistent nature of the flaw classified as CWE-80, Improper Neutralization of Script-Related HTML Tags in a Web Page. The vulnerability allows attackers to inject malicious JavaScript code through the configuration interface, which gets stored on the server and subsequently executed whenever the page is accessed by any user. The flaw occurs because the web application fails to properly escape or validate user input before rendering it back to the browser, creating an environment where attacker-controlled JavaScript can persist and execute in the context of other users' sessions.
The operational impact of this vulnerability extends beyond simple code injection, as it enables attackers to establish persistent access to the device management interface and potentially compromise the entire IoT deployment. An attacker could inject malicious scripts that steal session cookies, redirect users to phishing sites, or execute arbitrary commands on the device. This vulnerability particularly affects constrained devices operating in sensitive environments such as industrial control systems, smart grid infrastructure, or building automation systems where unauthorized access could lead to operational disruptions or security breaches. The persistent nature of the vulnerability means that once exploited, the malicious code remains active until manually removed from the configuration page, providing attackers with sustained access to the device management interface.
Mitigation strategies for CVE-2017-7296 should focus on implementing proper input validation and output encoding mechanisms within the web server component. Organizations should ensure that all user-provided data is properly sanitized before being processed or stored, utilizing established security libraries or frameworks that handle HTML escaping and input validation. The recommended approach involves implementing a whitelist-based input validation system that only accepts known good characters and patterns, while also employing proper output encoding for any data rendered to web pages. Additionally, implementing strict access controls and network segmentation can limit the potential impact of exploitation, as can regular firmware updates and security audits of embedded systems. The vulnerability demonstrates the importance of security-by-design principles in IoT implementations, where traditional web application security practices must be adapted for resource-constrained environments. This flaw also aligns with ATT&CK technique T1059.007, Command and Scripting Interpreter: JavaScript, highlighting the need for robust input validation in web-based interfaces. Organizations should also consider implementing web application firewalls and monitoring for suspicious HTTP POST requests to detect potential exploitation attempts.