Welcome back all l33ts :-)
Today i am going to show you that how i got Brute Force Attack Vulnerability in Facebook "Facebook Brute Force" Attack Vulnerability ( Reported On 11-4-2013 )
first we have to know that what is Brute force attack vulnerability
According to OWASP
A common threat web developers face is a password-guessing attack known as a brute force attack. A brute-force attack is an attempt to discover a password by systematically trying every possible combination of letters, numbers, and symbols until you discover the one correct combination that works. If your web site requires user authentication, you are a good target for a brute-force attack etc. :-)
So lets move to the interesting part