An Indian hacker has found a remarkably simple way to access any Facebook user account. Thankfully, Anand Prakash, a security engineer from Bangalore, is a “white hat” hacker and immediately contacted Facebook about the loophole, granting him a $15,000 reward.
In a blog post – with the provocative title “How I could have hacked all Facebook accounts” – Prakash explained the process he used, including a proof-of-concept video. Effectively, he brute-forced the password reset code – a six-digit number which is sent to the user’s phone or e-mail – on Beta version of Facebook, which allowed him unlimited input attempts without locking him out. He was then able to set his own password with which he could fraudulently access other user’s accounts.
“Whenever a user Forgets his password on Facebook, he has an option to reset the password by entering his phone number/ email address on https://www.facebook.com/login/identify?ctx=recover&lwv=110 ,Facebook will then send a 6 digit code on his phone number/email address which user has to enter in order to set a new password,” Prakash wrote. “I tried to brute the 6 digit code on www.facebook.com and was blocked after 10-12 invalid attempts.”
“Then I looked out for the same issue on beta.facebook.com and mbasic.beta.facebook.com and interestingly rate limiting was missing on forgot password endpoints,” he added. “I tried to takeover my account (as per Facebook’s policy you should not do any harm on any other users account) and was successful in setting new password for my account. I could then use the same password to login in the account.”
According to his blog, Prakash discovered the vulnerability on 22nd February, and received his $15,000 reward from Facebook on 2nd March. Facebook is yet to confirm the veracity of Prakash’s blog post.