A Multilevel Approach to TARA: Proposals for Attack Feasibility in Interference‐Free Scenarios

ABSTRACT Automotive SPICE for Cybersecurity incorporates the Cybersecurity Risk Management process (MAN.7), aligning with the Risk Assessment methods defined in ISO/SAE 21434:2021 (Clause 15). Both standards provide guidance on conducting Threat Analysis and Risk Assessments (TARA). However, they do not specify how to integrate the determination of attack feasibility when multiple TARAs emerge across different development phases. This paper explores how the concept of freedom from interference can facilitate a unified approach to determining attack feasibility in such scenarios.