Cars and Voting Machines: Embedded Systems in the Field

The second talk on the final day of the “Is Cryptographic Theory Practically Relevant?” workshop  was about exploiting some weaknesses in embedded systems used in some real-life applications and was given by Hovav Shacham. The talk summarizes the result of a comprehensive study undertaken by many researchers and its aim was to investigate and exploit vulnerabilities in embedded systems used in real life; in particular, the study was concerned with automobiles and voting machines.

All modern cars rely on computerized units to achieve different functionalities related to efficiency, entertainment, safety and security. Although there exist attacks which require access to the car, the study was more concerned with vulnerabilities which could be exploited remotely (i.e. without requiring physical access to the car) via different communication channels such as Bluetooth, WiFi and other channels which are used for instance for crash warning etc.

The team involved in the study developed a software that listens to communication between the different components in the car or between the car and the outside world, and then injects some messages to force some malicious behaviour. Exploiting some vulnerabilities, the study showed that an attacker could take complete control of many components in the car. Such vulnerabilities allowed the attacker to, for instance, disable the brake system, control the readings of the speedometer and lock the driver in.

The study also investigated some vulnerabilities in the context of voting via voting marines. Such machines are required to incorporated some basic checks to ensure the correctness and the fairness of the outcome of a vote. For instance, a mechanism to ensure that a voter can only vote once is required.

The attacks mounted only required access to the machines themselves and did not require access to neither the underlying source code nor the vendor's manual.

Those vulnerabilities are serious because of the communication capabilities which could affect not only a single car itself but an entire network.

Most of the vulnerabilities are an obvious result of the designers failing to understand cryptography and therefore resulting them getting even the simplest requirements wrong. Besides other security flaws, the attacks exploited the absence of proper communication authentication and the lack of sufficient mechanisms to protect the memory content of the computerized components.