Security Analysis of Contiki IoT Operating System

The Internet of Things (IoT) has introduced a myriad of ways in which devices can interact with each other. The IoT concept provides opportunities for novel and useful applications but at the same time, concerns have been raised over potential security issues caused by buggy IoT software. It is therefore imperative to detect and fix these bugs in order to minimise the risk of IoT devices becoming the target or source of attacks. In this paper, we focus our investigation on the underlying IoT operating system (OS), which is critical for the overall security of IoT devices. We picked Contiki as our case study since it is a very popular IoT OS and we have access to part of the development team, allowing us to discuss potential vulnerabilities with them so that fixes can be implemented quickly. Using static program analysis tools and techniques, we are able to scan the source code of the Contiki OS systematically in order to identify, analyse and patch vulnerabilities. Our main contribution is a holistic and systematic analysis of Contiki, starting with an exploration of its metrics, fundamental architecture, and finally some of its vulnerabilities. Our analysis produced relevant data on the number of unsafe functions in use, as well as the bug density; both of which provide an indication of the overall security of the inspected system. Our effort led to the finding of two major issues, described in two Common Vulnerabilities and Exposures (CVE) reports.