Admin Forums safe?

[Yoo2]

I was wondering if there is a way users can gain access to admin accounts. It seems a simply password cracker could gain access to the admin forums without much trouble.

Heres an example:
removed
Is this easy to bypass? How is it done? How can I fix it? thx.

[Admin]

Yoo2, please go to this (http://www.vbulletin.com/members/vbulletin.org.php) page and enter your username, to show you are licensed. (you will need to use your customer number and password to access that page)
Thank you.