Improving MQTT Security Through the Generation of Malicious Test Cases

The pervasive deployment of IoT technologies accounts for a variety of hazards often requiring a cross-layer approach. For example, the security posture of brokers responsible for handling the Message Queuing Telemetry Transport (MQTT) protocol has to be assessed at different functional layers, thus it is important to generate test cases ranging from network traffic conditions to application-specific patterns. Alas, this is a time consuming and poorly-generalizable process. Therefore, this paper proposes two frameworks for improving IoT security. The first is a suite for creating traffic flows starting from real traces or arbitrary configurations. The second is a Small Language Model that can produce realistic MQTT topics. To demonstrate their effectiveness, we showcase how they can be used to mitigate covert communications targeting IoT ecosystems. Results indicate that our tools can provide realistic test conditions for advancing IoT security, especially to better comprehend attacks targeting the MQTT protocol.