The Controller Area Network (CAN) bus is a serial bus protocol widely used in the automotive domain to allow communication between different Electronic Control Units in the car. This communication peripheral has been developed with the goal of having robust systems with respect to external noise, hence the typical application in automotive-oriented products. Being often part of safety-critical systems, the hardware implementing the CAN network must be constantly tested along the system lifetime, even during the operational phase. CAN controllers are complex modules in charge of managing the sending and the receiving of packages through the CAN bus and defects affecting them can easily compromise the whole CAN network.