I'm not sure that's even possible. I could be mistaken but brakes are designed to be resilient to failure to the point that there aren't really any common single points of failure in a modern car. Brake circuits are actually kept separate from the master cylinder on down so that if one of the seals blows out on the master cylinder there's still another seal for the other circuit. If there's a cut in one of the brake hoses and the fluid leaks out, the brake fluid reservoir splits into two sections at the bottom so that even if one leaks to the point of being bone dry the other side still has some fluid left. The brake booster is designed so that it's a solid piece going all the way through it so if the brake booster is totally broken it works like a linkage. The brake booster is also designed with a check valve so that even after the engine is turned off you still have some vacuum stored in the booster for a couple presses of the pedal before the brake assist stops.

I'm not saying that there couldn't be a failure mode that would prevent someone from using the brakes but due to the attention to detail for everything else about the design and redundancy of the braking system on a car I think it's doubtful that the ABS actuator would be designed in such a way as to allow a software error or broken part to potentially prevent the brakes from working.