Response pool use-after-free memory corruption error
SOURCE:

http://bugs.proftpd.org/show_bug.cgi?id=3711

Seems like an update to either 1.3.3g or 1.3.4 will fix this issue. The current psa-proftpd version in Atomic is 1.3.3e.

The ASL kernel makes you immune to this class of vulnerability already. If you are not using the ASL kernel, then you are not immune to this entire class of vulnerability (regardless of what application may have this kind of vulnerability - which could be anything not just proftp).

For those users that are not using the ASL kernel we highly recommend you run the ASL kernel so you too can be immune to whole classes of vulnerabilities like this one.

And for those that choose to run an insecure kernel, we will be releasing an update for proftp. You will still, of course, be vulnerable to any future (or current) vulnerabilities like this one in any other application.

So, just to recap, if you are using the ASL kernel you do not need to worry about this, you are immune.