While this is one instance of public proof of concept exploit, it would be foolish to think only these locations are subject. The full range of data driven and other exploits against both online and mail balloting is very large. If you can dream up a few exploits for just one system, you can bet the rest are equally exploitable, and are being exploited. Until the retarded, unfair, unfree, involuntary, sanctioned force of democracy voting (by definition the violent majority abusing the harmless minority upon threat of death), falls out of favor towards free voluntary association... The planet should move back to modified old India style... no registration, ID, or any restrictions... just chemically skin binding ink dip, hard physical ballots, human and computer countable, with a serially matching receipt suitable for revocation contingencies until tallied. Cheap, easy, reliable, has worked ever since humans decided to start voting. Just because you think you can make anything and everything in life digital, doesn't mean you should ever actually try to do it.
I do not know when this system was implemented
Though perhaps by dumb democrats in the failed democrat run inner cities where these systems reside, lol. Try compiling a national study of who first drafted each proposal later enacted, to move places off strict physical in person... maybe you will discover some interesting pattern. Get rid of such gigantic entrenched tentacled systems of unfreedom and control... your life will have more freedom.