This year at the DEF CON hacking conference in Las Vegas, 30 computer-powered ballot boxes used in American elections were set up in a simulated national White House race – and hackers got to work physically breaking the gear open to find out what was hidden inside.

In less than 90 minutes, the first cracks in the systems’ defenses started appearing, revealing an embarrassing low level of security. Then one was hacked wirelessly.
The machines – from Diebolds to Sequoia and Winvote equipment – were bought on eBay or from government auctions, and an analysis of them at the DEF CON Voting Village revealed a sorry state of affairs. Some were running very outdated and exploitable software – such as unpatched versions of OpenSSL and Windows XP and CE. Some had physical ports open that could be used to install malicious software to tamper with votes.

Source: It took DEF CON hackers minutes to pwn these US voting machines