Seems like there never were security issues. At least, none that were talked about widely.
I think that should be expected for a single player game. 
Almost all games are hack-able in some way of course but hacking a single player game is mostly an exercise in replay-ability.<p>On a related note: 
Doom apparently does contribute to security proof of concepts though.  
<a href="http:&#x2F;&#x2F;www.techtimes.com&#x2F;articles&#x2F;15606&#x2F;20140916&#x2F;security-expert-hacks-canon-pixma-printer-to-play-doom-highlights-security-weakness.htm" rel="nofollow">http:&#x2F;&#x2F;www.techtimes.com&#x2F;articles&#x2F;15606&#x2F;20140916&#x2F;security-ex...</a><p>Which makes me wonder if the non-clearing memory issue exists for the printer&#x27;s video driver and whether that could be used to retrieve something like a saved password or ssh key.