This week’s breach of Sarah Palin’s Yahoo Mail account has been much discussed. One aspect that has gotten less attention is how the breach occurred, and what it tells us about security and online behavior.
(My understanding of the facts is based on press stories, and on reading a forum post written by somebody claiming to be the perpetrator. I’m assuming the accuracy of the forum post, so take this with an appropriate grain of salt.)
The attacker apparently got access to the account by using Yahoo’s password reset mechanism, that is, by following the same steps Palin would have followed had she forgotten her own password.
Yahoo’s password reset mechanism is surprisingly weak and easily attacked. To simulate the attack on Palin, I performed the same “attack” on a friend’s account (with the friend’s permission, of course). As far as I know, I followed the same steps that the Palin attacker did.
First, I went to Yahoo’s web site and said I had forgotten my password. It asked me to enter my email address. I entered my friend’s address. It then gave me the option of emailing a new password to my friend’s alternate email address, or doing an immediate password reset on the site. I chose the latter. Yahoo then prompted me with my friend’s security question, which my friend had previously chosen from a list of questions provided by Yahoo. It took me six guesses to get the right answer. Next, Yahoo asked me to confirm my friend’s country of residence and zip code — it displayed the correct values, and I just had to confirm that they were correct. That’s all! The next step had me enter a new password for my friend’s account, which would have allowed me to access the account at will.
The only real security mechanism here is the security question, and it’s often easy to guess the right answer, especially given several tries. Reportedly, Palin’s question was “Where did you meet your spouse?” and the correct answer was “Wasilla high”. Wikipedia says that Palin attended Wasilla High School and met her husband-to-be in high school, so “Wasilla high” is an easy guess.
This attack was not exactly rocket science. Contrary to some news reports, the attacker did not display any particular technical prowess, though he did display stupidity, ethical blindness, and disrespect for the law — for which he will presumably be punished.
Password recovery is often the weakest link in password-based security, but it’s still surprising that Yahoo’s recovery scheme was so weak. In Yahoo’s defense, it’s hard to verify that somebody is really the original account holder when you don’t have much information about who the original account holder is. It’s not like Sarah Palin registered for the email account by showing up at a Yahoo office with three forms of ID. All Yahoo knows is that the original account holder claimed to have the name Sarah Palin, claimed to have been born on a particular date and to live in a particular zip code, and claimed to have met his/her spouse at “Wasilla high”. Since this information was all in the public record, Yahoo really had no way to be sure who the account holder was — so it might have seemed reasonable to give access to somebody who showed up later claiming to have the same name, email address, and spouse-meeting place.
Still, we shouldn’t let Yahoo off the hook completely. Millions of Yahoo customers who are not security experts (or are security experts but want to delegate security decisions to someone else) entrusted the security of their email accounts to Yahoo on the assumption that Yahoo would provide reasonable security. Palin probably made this assumption, and Yahoo let her down.
If there’s a silver lining in this ugly incident, it is the possibility that Yahoo and other sites will rethink their password recovery mechanisms, and that users will think more carefully about the risk of email breaches.
