Sixapart’s site error

There is a bug in the Sixapart’s site, under plugin part.
I sent a notice to them two days ago. When I checked it now, the bug is still there.
What’s wrong with their site?
Going to the Plugins Directory of Sixapart. The form Plugin Search is used to search plugin you need.
If you enter some name like “spam”, the results are good for you. It returns SpamLookup, quasi-spamfilter, etc. You can choose one from them.
The problem is when you enter “meta”, it gives you an error screen.
It said:

An error occurred:
Can’t call method “id” on an undefined value at /var/www/vhosts/sixapart.com/htdocs/mt-plugins/lib/MT/Template/Context.pm line 2563.

The screen shots shown as below:
sixapart-meta-error


sixapart-meta-error-result

Until now, they have not fix this bug of their site.
I am not a hacker and I know nothing about it. The real hacker can use this site leak to do more things.