Microsoft
quietly fixed a flaw in Hotmail's password reset system that allowed anyone to reset the password of any Hotmail account last Friday. The company was notified of the flaw on April 20th and responded with a fix within hours—but not until after widespread attacks, with the bug
apparently spreading "like wild fire" in the hacking community.
Hotmail's password reset system uses a token system to ensure that only the account holder can reset their password: a link with the token is sent to an account linked to the Hotmail account, and clicking the link lets the account owner reset their password. However, the validation of these tokens isn't handled properly by Hotmail, allowing attackers to reset passwords of any account.
Initially hackers were offering to crack accounts for $20 a throw. However, the technique became publicly known and started to
spread rapidly with
Web and
YouTube tutorials showing the technique popping up across the Arabic-speaking Internet. Videos showing the technique (or at least, something close to it) can be found as far back as
April 6th.
