1.5.3 The Jeep hack

At the BlackHat 2015 conference, security researchers Charlie Miller and Chris Valasek demonstrated the first remote attack on an unaltered, factory passenger car [120]. In what later became known as the Jeep hack, the researchers demonstrated how the vehicle’s infotainment system, Uconnect, which has both remote connectivity as well as the capability to communicate with other electronic control units within the vehicle, can be used for remote attacks.

Specifically, while systematically examining the vehicle’s attack surface, the researchers discovered an open D-Bus over an IP port on Uconnect, which is essentially an inter-process communication and remote procedure call mechanism. The D-Bus service accessible via the open port allows anyone connected to the infotainment system to execute arbitrary code in an unauthenticated manner.

Miller and Valasek also discovered that the D-Bus port was bound to all network interfaces on the vulnerable Uconnect infotainment system and was therefore accessible remotely over the Sprint mobile network that Uconnect uses for telematics. By connecting to the Sprint network using a femtocell or simply a regular mobile phone, the researchers were able to send remote commands to the vehicle.

From that entry point, Miller and Valasek attacked a chip in the vehicle’s infotainment system by re-writing its firmware to be able to send arbitrary commands over the vehicle’s internal CAN communication network, effectively giving them the ability to completely take over the vehicle.

1.5.4 Commonalities

What do these examples have in common and how does it relate to cryptography? In a nutshell, these examples illustrate what happens in the absence of appropriate cryptography. In all three cases discussed, there was no mechanism in place to verify that the systems were talking to legitimate users and that the messages received were not manipulated while in transit.

In the Mirai example, anyone with knowledge of the IoT devices’ IP addresses would have been able to access their login page. This information can be easily collected by scanning the public internet with tools such as nmap. So the designers’ assumption that the users would change the default device password to a strong individual one was the only line of defense. What the security engineers should have done instead is to add a cryptographic mechanism to give access to the login procedure only to legitimate users, for example, users in possession of a digital certificate or a private key.

In the case of Operation Aurora, the perimeter defense doctrine used by the affected companies treated every device within the trusted perimeter (typically, within a corporate network) as trustworthy by default. On this premise, every device inside the perimeter had access to all resources and systems within that perimeter.

As a result, anyone able to walk inside a company building or trick an arbitrary employee into clicking on a malicious link and infect their computer with malware would have been able to access all systems within the perimeter.

As a response to Operation Aurora, Google and other companies replaced perimeter defense with a zero trust security model that establishes trust by evaluating it on a per-transaction basis instead of basing trust on the network location (the perimeter) [155]. At the core of the zero trust security model is the ability to securely authenticate users and resources in order to prevent unauthorized access to data and services. Secure authentication, in turn, is built upon cryptography.

Finally, in the Jeep hack example, the open D-Bus over IP port allowed anyone connected to the vehicle’s infotainment system to execute arbitrary code in an unauthenticated manner. The possibility to access the vehicle remotely over the Sprint mobile network further increased the range of the attack. The system’s designers apparently assumed that the Sprint mobile network is a secure perimeter. What they should have done instead is to add a cryptographic mechanism to ensure that only legitimate users could log in to the Uconnect system.

1.6 Summary

In this chapter, we have provided an overview of the recent history of cryptography, starting in the 1970s, and identified some global trends that explain why cryptography has become more and more important over the last few decades, to a point where it is practically around you every time you access the internet or use a connected device. In the next chapter, you will learn about the general goals and objectives you can achieve with the help of cryptography. In particular, you will get to know cryptography’s main protagonists, Alice and Bob, and their ubiquitous opponents, Eve and Mallory.