I will do my best to answer that. Normally, we have to take all of the surrounding details of a particular deployment into account when we explain something like this.
Typically speaking, in the more recent versions of equipment like this, they are starting to emerge now with embedded hard drives and USB ports that can be used for maintenance purposes for uploading and downloading data and software updates and that sort of thing. In the truest sense of the word, those would indeed give vectors for something like that to be done with malicious intent.