Security

I'm not an expert of security, but need to run my software in security environment. This means, software will be run on PC, that will be put inside special box, that disables for user to connect USB or network devices without destroying this special box.

What I need is to allow for user to connect his own microphone to jack port. Do you think, is there any risk to attack somehow such system just by sending special signals on jack port?

No decided about this PC architecture or system. Would like to analyze first, if there are any known attacks using jack port.