I doubt it’s a target unless someone was actively profiling the company in question, building out a plan, and seeking to actively exploit the company’s network from that machine. Even then, how many attackers know IRIX well enough to pull it off?

If we were talking about a networked DOS machine, Windows XP, or even classic MacOS this lack of updates would be more serious… but niche UNIX workstations? Not as certain they’re still targets.

It wasn’t that secure from the start. The lpr user was a nice way to get into Irix.

That said, my favorite Unix.

It definitely wasn't! I remember the irix 5.x and earlier days. By default, it shipped without any X11 authentication enabled. This meant everyone on the network could keylog your machine.