Automated Fuzzing of Automotive Control Units

TL;DR

This paper introduces an automated fuzzing approach for automotive ECUs that uses sensor data and oracle functions to detect system changes, enhancing security testing of vehicle communication networks.

Contribution

It presents a systematic method for fuzzing CAN networks with sensor-based oracle functions, enabling high-automation detection of ECU states in automotive systems.

Findings

Successfully identified ECU states in commercial vehicle clusters

Demonstrated high automation in detecting system responses

Applicable to distributed cyber-physical systems beyond automotive

Abstract

Modern vehicles are governed by a network of Electronic Control Units (ECUs), which are programmed to sense inputs from the driver and the environment, to process these inputs, and to control actuators that, e.g., regulate the engine or even control the steering system. ECUs within a vehicle communicate via automotive bus systems such as the Controller Area Network (CAN), and beyond the vehicles boundaries through upcoming vehicle-to-vehicle and vehicle-to-infrastructure channels. Approaches to manipulate the communication between ECUs for the purpose of security testing and reverse-engineering of vehicular functions have been presented in the past, all of which struggle with automating the detection of system change in response to message injection. In this paper we present our findings with fuzzing CAN networks, in particular while observing individual ECUs with a sensor harness. The harness detects physical responses, which we then use in a oracle functions to inform the fuzzing process. We systematically define fuzzers, fuzzing configurations and oracle functions for testing ECUs. We evaluate our approach based on case studies of commercial instrument clusters and with an experimental framework for CAN authentication. Our results show that the approach is capable of identifying interesting ECU states with a high level of automation. Our approach is applicable in distributed cyber-physical systems beyond automotive computing.