WeepingCAN: A Stealthy CAN Bus-off Attack

The controller area network (CAN) is a high-value asset to defend and attack in automobiles. The bus-off attack exploits CAN’s fault confinement to force a victim electronic control unit (ECU) into the bus-off state, which prevents it from using the bus. Although pernicious, the bus-off attack has two distinct phases that are observable on the bus and allow the attack to be detected and prevented. In this paper we present WeepingCAN, a refinement of the bus-off attack that is stealthy and can escape detection. We evaluate WeepingCAN experimentally using realistic CAN benchmarks and find it succeeds in over 75% of attempts without exhibiting the detectable features of the original attack. We demonstrate WeepingCAN on a real vehicle.