CVE-2018-6906 in RainMachine Mini-8
Summary
by MITRE
A persistent Cross Site Scripting (XSS) vulnerability in the Green Electronics RainMachine Mini-8 (2nd Generation) and Touch HD 12 web application allows an attacker to inject arbitrary JavaScript via the REST API.
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Analysis
by VulDB Data Team • 04/09/2020
The CVE-2018-6906 vulnerability represents a critical persistent cross site scripting flaw affecting Green Electronics RainMachine Mini-8 (2nd Generation) and Touch HD 12 devices. This vulnerability resides within the web application interface of these smart irrigation controllers, which are designed for automated watering systems in residential and commercial environments. The flaw enables attackers to execute malicious JavaScript code through the device's REST API endpoints, creating a significant security risk for users who rely on these systems for environmental automation and control. The vulnerability's persistence nature means that malicious payloads injected through the API can remain active and execute across multiple user sessions, potentially compromising long-term system integrity.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the RainMachine web application's API handlers. When legitimate users interact with the device through the web interface or mobile applications, the system fails to properly sanitize user-supplied data that gets processed through the REST API endpoints. This allows attackers to craft malicious payloads that bypass standard security measures, particularly when the application fails to properly encode or escape special characters in user-controllable input fields. The vulnerability specifically affects the device's handling of data submitted through API calls, where the system stores and displays user input without adequate protection against script injection attacks. This represents a classic CWE-79: Cross-site Scripting vulnerability where the application fails to validate or sanitize user-provided data before incorporating it into dynamically generated web content.
The operational impact of this vulnerability extends beyond simple script execution, creating substantial risks for both individual users and potential attackers seeking to exploit connected systems. An attacker could leverage this vulnerability to steal user session cookies, redirect victims to malicious sites, or perform unauthorized actions within the device's administrative interface. The persistent nature of the XSS allows attackers to maintain access across multiple sessions, potentially enabling long-term surveillance or control of the irrigation system. This threat is particularly concerning for users who might have sensitive data or control access to water systems that could be manipulated for malicious purposes. The vulnerability could also facilitate more sophisticated attacks such as credential theft, data exfiltration, or even physical security compromise if the irrigation system is integrated with other smart home or building management systems. The device's web interface typically provides administrative controls for scheduling, configuration, and monitoring, making it an attractive target for attackers seeking persistent access to environmental control systems.
Mitigation strategies for CVE-2018-6906 should focus on immediate remediation through firmware updates provided by Green Electronics, while also implementing network-level protections such as web application firewalls and network segmentation. Users should disable remote access to the device when not actively required and ensure all systems are running the latest firmware versions. Network administrators should monitor for suspicious API activity and implement proper input validation at the network perimeter. The vulnerability's classification under ATT&CK technique T1059.007 (Command and Scripting Interpreter: JavaScript) highlights the need for comprehensive security monitoring of script execution within the device's web environment. Additionally, users should regularly audit their device configurations and implement multi-factor authentication where available to reduce the attack surface for potential exploitation. Organizations managing multiple RainMachine devices should consider implementing centralized monitoring solutions to detect anomalous API usage patterns that might indicate exploitation attempts. The vulnerability underscores the importance of secure coding practices and input validation in IoT devices, particularly those handling user-controllable data through web interfaces.