In the U.S., voting machines have only insignificant intrusion protection.

A contest was held earlier this year, in which hackers at the DEF CON convention were challenged to break into a number of examples purchased on eBay, government auctions, etc. 

Took about 90 minutes.  Read about it here among other places: https://www.theregister.co.uk/2017/07/29/us_voting_machines_hacking/

Stephen J. Remington