Elgg 2.3 protection issue

Hi everybody,

I think this problem can be touching everybody who use this cms to his social network.
I use elgg in a boundle with the Profile manager, social bootstrap theme and other modules, including custom additional.

I added few fields throught Profile manager form and made it mandatory for registration form, as a full name, date of birht and so on. But recently somebody registered bypassing these mandatory fields. I cound't find for now how it is possible.
Where can be hole? 
Will be glad for any help, thank you.