Authorization under admins, even if you enter nonsense into the form, how so?

Question

1C-Bitrix

Hello!
Someone came across such that when you enter into the authorization form on the site, you log in as an administrator.
Even if you do not enter anything into the fields, you still get into the admin panel, but if you enter /bitrix/ , then everything is ok.
It's not very clear, has anyone had a similar experience?