Never Ending Story: Authentication and Access Control Design Flaws in Shared IoT Devices

Internet-of-Things (IoT) devices implement weak authentication and access control schemes. The on-demand nature of IoT devices requires a responsive communications channel, which is often at odds with thorough authentication and access control. This paper seeks to better understand IoT device security by examining the design of authentication and access control schemes. In this work, we explore the challenge of propagating credential revocation and access control list modifications in a shared IoT ecosystem. We evaluate the vulnerability of 19 popular security cameras and doorbells against a straightforward user-interface bound adversary attack. Our results demonstrate that 16 of 19 surveyed devices suffer from flaws that enable unauthorized access after credential modification or revocation. We conclude by discussing these findings and propose a means for balancing authentication and access control schemes while still offering responsive communications channels.