Ulf E. Larson

Bio: Ulf E. Larson is an academic researcher from Chalmers University of Technology. The author has contributed to research in topics: Intrusion detection system & Firmware. The author has an hindex of 14, co-authored 33 publications receiving 936 citations. Previous affiliations of Ulf E. Larson include Ericsson.

An approach to specification-based attack detection for in-vehicle networks

Abstract: An upcoming trend for automotive manufacturers is to create seamless interaction between a vehicle and fleet management to provide remote diagnostics and firmware updates over the air. To allow this, the previously isolated in-vehicle network must be connected to an external network, and can thus be exposed to a whole new range of threats known as cyber attacks. In this paper we explore the applicability of a specification-based approach to detect cyber attacks within the in-vehicle network. We derive information to create security specifications for communication and ECU behavior from the CANopen draft standard 3.01 communication protocol and object directory sections. We also provide a set of example specifications, propose a suitable location for the attack detector, and evaluate the detection using a set of attack actions.

Efficient In-Vehicle Delayed Data Authentication Based on Compound Message Authentication Codes

Abstract: Modern vehicles contain an in-vehicle network consisting of a number of electronic control units (ECUs). These ECUs are responsible for most of the functionality in the vehicle, including vehicle control and maneuverability. To date, no security features exist in this network since it has been isolated. However, an upcoming trend among automobile manufacturers is to establish a wireless connection to the vehicle to provide remote diagnostics and software updates. As a consequence, the in-vehicle network is exposed to external communication, and a potential entry point for attackers is introduced. Messages sent on the in-vehicle network lack integrity protection and data authentication; thus, the network is vulnerable to injection and modification attacks. Due to the real-time constraints and the limited resources in the ECUs, achieving data authentication is a challenge. In this paper, we propose an efficient delayed data authentication using compound message authentication codes. A message authentication code is calculated on a compound of successive messages and sent together with the subsequent messages, resulting in a delayed authentication. This data authentication could be used to detect and possibly recover from injection and modification attacks in the in-vehicle network.

Secure Firmware Updates over the Air in Intelligent Vehicles

Abstract: Modern intelligent vehicles have electronic control units containing firmware that enables various functions in the vehicle. New firmware versions are constantly developed to remove bugs and improve functionality. Automobile manufacturers have traditionally performed firmware updates over cables but in the near future they are aiming at conducting firmware updates over the air, which would allow faster updates and improved safety for the driver. In this paper, we present a protocol for secure firmware updates over the air. The protocol provides data integrity, data authentication, data confidentiality, and freshness. In our protocol, a hash chain is created of the firmware, and the first packet is signed by a trusted source, thus authenticating the whole chain. Moreover, the packets are encrypted using symmetric keys. We discuss the practical considerations that exist for implementing our protocol and show that the protocol is computationally efficient, has low memory overhead, and is suitable for wireless communication. Therefore, it is well suited to the limited hardware resources in the wireless vehicle environment.

A First Simulation of Attacks in the Automotive Network Communications Protocol FlexRay

Abstract: The automotive industry has over the last decade gradually replaced mechanical parts with electronics and software solutions. Modern vehicles contain a number of electronic control units (ECUs), which are connected in an in-vehicle network and provide various vehicle functionalities. The next generation automotive network communications protocol FlexRay has been developed to meet the future demands of automotive networking and can replace the existing CAN protocol. Moreover, the upcoming trend of ubiquitous vehicle communication in terms of vehicle-to-vehicle and vehicle-to-infrastructure communication introduces an entry point to the previously isolated in-vehicle network. Consequently, the in-vehicle network is exposed to a whole new range of threats known as cyber attacks. In this paper, we have analyzed the FlexRay protocol specification and evaluated the ability of the FlexRay protocol to withstand cyber attacks. We have simulated a set of plausible attacks targeting the ECUs on a FlexRay bus. From the results, we conclude that the FlexRay protocol lacks sufficient protection against the executed attacks, and we therefore argue that future versions of the specification should include security protection.

Securing vehicles against cyber attacks

Abstract: The automobile industry has grown to become an integral part of our everyday life. As vehicles evolve, the primarily mechanical solutions for vehicle control are gradually replaced by electronics and software solutions forming in-vehicle computer networks. An emerging trend is to introduce wireless technology in the vehicle domain by attaching a wireless gateway to the in-vehicle network. By allowing wireless communication, real-time information exchange between vehicles and between infrastructure and vehicles become reality. This communication allows for road condition reporting, decision making, and remote diagnostics and firmware updates over-the-air. However, allowing external parties wireless access to the in-vehicle network creates a potential entry-point for cyber attacks. In this paper, we investigate the security issues of allowing external wireless communication. We use a defense-in-depth perspective and discuss security challenges for each of the prevention, detection, deflection, countermeasures, and recovery layers.

Experimental Security Analysis of a Modern Automobile

Abstract: Modern automobiles are no longer mere mechanical devices; they are pervasively monitored and controlled by dozens of digital computers coordinated via internal vehicular networks. While this transformation has driven major advancements in efficiency and safety, it has also introduced a range of new potential risks. In this paper we experimentally evaluate these issues on a modern automobile and demonstrate the fragility of the underlying system structure. We demonstrate that an attacker who is able to infiltrate virtually any Electronic Control Unit (ECU) can leverage this ability to completely circumvent a broad array of safety-critical systems. Over a range of experiments, both in the lab and in road tests, we demonstrate the ability to adversarially control a wide range of automotive functions and completely ignore driver input\dash including disabling the brakes, selectively braking individual wheels on demand, stopping the engine, and so on. We find that it is possible to bypass rudimentary network security protections within the car, such as maliciously bridging between our car's two internal subnets. We also present composite attacks that leverage individual weaknesses, including an attack that embeds malicious code in a car's telematics unit and that will completely erase any evidence of its presence after a crash. Looking forward, we discuss the complex challenges in addressing these vulnerabilities while considering the existing automotive ecosystem.

Comprehensive experimental analyses of automotive attack surfaces

Abstract: Modern automobiles are pervasively computerized, and hence potentially vulnerable to attack. However, while previous research has shown that the internal networks within some modern cars are insecure, the associated threat model--requiring prior physical access--has justifiably been viewed as unrealistic. Thus, it remains an open question if automobiles can also be susceptible to remote compromise. Our work seeks to put this question to rest by systematically analyzing the external attack surface of a modern automobile. We discover that remote exploitation is feasible via a broad range of attack vectors (including mechanics tools, CD players, Bluetooth and cellular radio), and further, that wireless communications channels allow long distance vehicle control, location tracking, in-cabin audio exfiltration and theft. Finally, we discuss the structural characteristics of the automotive ecosystem that give rise to such problems and highlight the practical challenges in mitigating them.

Cyber-Physical Systems Security—A Survey

Abstract: With the exponential growth of cyber-physical systems (CPSs), new security challenges have emerged. Various vulnerabilities, threats, attacks, and controls have been introduced for the new generation of CPS. However, there lacks a systematic review of the CPS security literature. In particular, the heterogeneity of CPS components and the diversity of CPS systems have made it difficult to study the problem with one generalized model. In this paper, we study and systematize existing research on CPS security under a unified framework. The framework consists of three orthogonal coordinates: 1) from the security perspective, we follow the well-known taxonomy of threats, vulnerabilities, attacks and controls; 2) from the CPS components perspective, we focus on cyber, physical, and cyber-physical components; and 3) from the CPS systems perspective, we explore general CPS features as well as representative systems (e.g., smart grids, medical CPS, and smart cars). The model can be both abstract to show general interactions of components in a CPS application, and specific to capture any details when needed. By doing so, we aim to build a model that is abstract enough to be applicable to various heterogeneous CPS applications; and to gain a modular view of the tightly coupled CPS components. Such abstract decoupling makes it possible to gain a systematic understanding of CPS security, and to highlight the potential sources of attacks and ways of protection. With this intensive literature review, we attempt to summarize the state-of-the-art on CPS security, provide researchers with a comprehensive list of references, and also encourage the audience to further explore this emerging field.