Less time than voting

“In a few cases, the Voting Village's collection of hacker/researchers discovered that hacking the voting machines took less time than voting.”

Defcon Voting Village report: Bug in one system could “flip Electoral College” by Sean Gallagher, Ars Technica, 27 September 2018

The article continues,

One voting machine could be hacked in two minutes. And another hack, exploiting a flaw in an electronic card used to activate voting terminals, made it possible to reprogram the card wirelessly with a mobile device—allowing the voter to potentially cast as many votes as they like.

Perhaps the most frustrating of the problems documented by the researchers is that flaws, even when reported, don't get fixed. One example is another vulnerability in the ES&S M650 that had been reported more than 10 years ago to the manufacturer—but was still present on systems used for the 2016 election.