Integrating ISO/SAE 21434: A Comprehensive Analysis and Practical Implementation of Functional Cybersecurity Testing in Automotive Systems The automotive industry faces numerous cybersecurity challenges, highlighted by several high-profile incidents. In 2015, hackers exploited vulnerabilities in the Jeep Cherokee's infotainment system, gaining control of critical functions like braking and steering. In 2016, researchers remotely hacked the Tesla Model S's CAN bus, manipulating various systems, including the brakes. In 2020, hackers exploited the Tesla Model X's keyless entry system, allowing vehicle theft. These incidents emphasize the need for robust cybersecurity measures to prevent unauthorized access and ensure occupant safety. To mitigate identified risks, it is essential to implement a series of security requirements and to test their implementation.