The anti-theft protection mechanism can be bypassed by attackers due to weak response generation algorithms for the head unit. It is possible to reveal all 32 corresponding responses by sniffing CAN traffic or by pre-calculating the values, which allow to bypass the protection.
First identified on Nissan Leaf ZE1 manufactured in 2020.
Weakness
The device uses an algorithm that is predictable and generates a pseudo-random number.
Extended Description
Pseudo-random number generator algorithms are predictable because their registers have a finite number of possible states, which eventually lead to repeating patterns. As a result, pseudo-random number generators (PRNGs) can compromise their randomness or expose their internal state to various attacks, such as reverse engineering or tampering.