Threat Analysis and Risk Assessment of an Autonomous Roller

Sammanfattning

Background. As the road roller industry transitions toward more autonomoustechnology, the number of security vulnerabilities increases. Regulations such as theEuropean Union’s Cyber Resilience Act have made securing products with digital el-ements a priority. To identify and address threats and risks for autonomous rollers, athreat analysis and risk assessment can be performed, which also aids in compliancewith these emerging regulations. Objectives. This thesis aims to (1) model a reference architecture of an autonomousroller to enable a threat analysis and risk assessment. (2) Perform a threat analysisand risk assessment on the reference architecture to identify the threat scenarios andrisks to autonomous rollers. (3) Propose mitigations for the five most severe identi-fied risks of autonomous rollers. Methods. The reference architecture was created by integrating autonomous tech-nologies identified through a structured literature review with expert knowledge ofroad roller components and architecture obtained from an interview with expertsin the roller manufacturing industry. The threat analysis and risk assessment wasconducted based on ISO/SAE 21434, utilizing information from the structured lit-erature review, threat modeling with STRIDE, and logical inference based on thisinformation. Mitigation strategies for the most severe risks were identified using fromthe structured literature review and supplementary targeted academic literature. Results. A reference architecture of an autonomous roller was modeled with feed-back from and validation by industry experts. The threat analysis and risk assess-ment was successfully performed with a primary focus on five assets of the archi-tecture, with minor modifications to the focus group described in the standard andextensions made to the cybersecurity properties of an asset and the attack feasibilityrating step. A total of 15 threat scenarios and 42 risks associated with autonomousrollers were identified. The most severe identified risks were predominantly associ-ated with sensors, and several mitigations were proposed to reduce these risks. Conclusions. A threat analysis and risk assessment based on clause 15 in the rep-utable standard ISO/SAE 21434 can be performed to identify risks associated withautonomous rollers. The focus group outlined in the standard can be easily shiftedtoward more relevant group(s). Although the standard is best followed from thestart, it is possible to follow only the clause that outline the threat analysis and riskassessment process if sufficient research is made on the item of focus and its com-ponents. The large number of medium and severe risks identified for autonomousrollers highlights the importance of implementing comprehensive security controls tomitigate potential threats and minimize their impact, given that this work assumedthe absence of security controls unless they were explicitly mentioned.