IIRC either the original Xbox or the Xbox 360 was sometimes modded/jailbroken by using a modified firmware for the internal DVD drive. Not exactly the same thing, but in the same vein.
I could definitely see it being easy to write bugs where verification code assumes that nominally read-only devices always return the same data for two subsequent reads of the same location, and then getting up to mischief by taking advantage of that assumption.
