Was this attack addressed ?
See exploit-db listing here: https://www.exploit-db.com/exploits/31263/
Was this addressed / fixed ?
You're asking about a 1+ year-old exploit in an old version of pfSense? Considering how they're usually right on top of security vulns, I would assume that it has long since been fixed. If you need to confirm it, start reading through the various version release notes. Too bad there's no CVE ID to match against.
Some basic linux/unix bugs took 10+ years to get fixed, so I would assume: valid question…
That's a bug in snort, not pfSense per se.
I've done Nessus scans against pfSense that come up okay, so I wouldn't worry too much about this issue unless you have snort deployed. Additionally, I recommend reviewing the snort change log and current version to see if this was addressed.