CVE-2018-6012 in RainMachine Mini-8
Summary
by MITRE
The 'Weather Service' feature of the Green Electronics RainMachine Mini-8 (2nd generation) allows an attacker to inject arbitrary Python code via the 'Add new weather data source' upload function.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 04/09/2020
The CVE-2018-6012 vulnerability resides within the Green Electronics RainMachine Mini-8 (2nd generation) device, specifically targeting its Weather Service feature that enables users to add new weather data sources through an upload function. This device operates as a smart irrigation controller that integrates with various weather services to optimize watering schedules, making it a critical component in automated landscape management systems. The vulnerability manifests in the device's handling of user-uploaded weather data source files, where insufficient input validation allows for arbitrary code execution through Python code injection.
The technical flaw stems from improper validation of uploaded files within the device's web interface, specifically in the 'Add new weather data source' functionality. When users attempt to upload weather data files, the system fails to properly sanitize or validate the file contents before processing them as Python code. This creates a code injection vector where an attacker can craft malicious Python scripts within the uploaded file that will execute with the privileges of the web application process. The vulnerability is classified as a command injection flaw under CWE-77, where user-supplied data is directly executed as code without proper sanitization or context separation.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with full control over the device's operational capabilities. An attacker could potentially modify irrigation schedules, access sensitive user data, or even use the device as a pivot point for attacking other systems within the local network. The RainMachine device typically operates in residential or commercial environments where it may have network access and could serve as a gateway for broader network infiltration. This vulnerability aligns with ATT&CK technique T1059.006 for Python, where adversaries leverage scripting languages to execute malicious code on compromised systems.
The device's architecture presents additional risks as it likely operates with elevated privileges due to its role in managing environmental controls and potentially accessing network resources. The lack of proper file type validation and content sanitization creates a persistent threat vector that remains active as long as the device is operational and connected to a network. Mitigation strategies should focus on implementing strict file validation mechanisms, restricting file upload capabilities to verified formats only, and employing sandboxing techniques to isolate potentially malicious code execution. Additionally, network segmentation and regular firmware updates become critical defensive measures to limit the attack surface and ensure timely patch deployment. The vulnerability underscores the importance of input validation in IoT devices and highlights the need for secure coding practices in embedded systems that handle user-provided content.