Safety implications grow as vehicles rely more heavily on computers to control steering, braking and acceleration.
Documents allegedly referencing a Central Intelligence Agency mission to hack cars have sparked fears over vulnerabilities in autonomous vehicles.
The WikiLeaks document contains "vehicle systems" as an area of interest for the CIA's Embedded Devices Branch. It also includes QNX, an operating system used in many vehicles.
Automakers have faced criticism from the computer security industry in recent years as vehicles become more electronically integrated and come equipped with wireless communications systems. Together, these features provide pathways for hackers to remotely access a vehicle and control its systems, potentially including steering and acceleration.
Security researchers Charlie Miller and Chris Valasek in 2015 demonstrated how a vulnerability in Fiat Chrysler Automobiles' infotainment platform could be used to disable the brakes or manipulate steering. The findings prompted a recall for 1.4 million vehicles.
Speaking to The Washington Post about the WikiLeaks documents, Valasek warned that automakers do not appear to have any detection or prevention methods for such attacks.
"Remember, Charlie and I did all this research in our spare time with limited resources," he added.
The potential implications for fully autonomous vehicles are even more concerning, as all vehicle control systems will be managed by a central computer with a wireless Internet connection.
For ultimate Level 5 autonomy, in which a human driver can kick back and watch a movie while the vehicle drives itself, some automakers are exploring systems that would allow support 'drivers' to remotely operate an autonomous car without any human on board. Other automakers do not see the need for a steering wheel or other human controls in such vehicles.
WikiLeaks' warning of the CIA using hacked vehicles for "undetectable assassinations" might seem exaggerated with today's vehicles, but researchers warn that such a scenario may become increasingly plausible in coming years if automakers fail to address cybersecurity issues.