A Gateway-based MUD Architecture to Enhance Smart Home Security

Smart home systems, including consumer-grade Internet of Things (IoT) devices, are in a dangerous situation. On the one hand, the number of smart homes is increasing. On the other hand, the devices in these dwellings are often affected by vulnerabilities that could be exploited to generate massive (distributed) attacks. To mitigate the issue of having compromised devices involved in such attacks, the Internet Engineering Task Force (IETF) recently proposed a new standard: the Manufacturer Usage Description (MUD).The main contribution of this paper is to propose a slightly extended version of the MUD architecture. This architecture is centered around a smart home gateway (SHG) that can be extended through the contributions of plug-in developers. Indeed, our proposed approach allows developers to specify which endpoints their plug-ins need to reach. These requirements will then be processed to generate a consolidated gateway-level MUD file exposed by the SHG itself. Thus, thanks to this solution and developers’ intervention, even devices that are not natively "MUD-enabled" would be protected by the MUD standard if integrated through a proper plug-in. Moreover, these requirements are transparent for the device itself.To demonstrate the feasibility of this approach, we realized a proof-of-concept for a widespread open-source smart home gateway: Home Assistant.