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Hackers Can Delete Facebook Friends, Thanks to Flaw

pcworld.com

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Re: Hackers Can Delete Facebook Friends, Thanks to Flaw

#4
Original story without the splash page:

http://prominentsecurity.com/?p=119

It also says that the flaw has been patched:

"*Update (5/22/10): After reporting the flaw to Facebook Wednesday afternoon, I have confirmed as of Friday afternoon that the flaw has been successfully patched. Facebook now strictly enforces the existence of the “post_form_id” CSRF protection token in the request."

Re: Hackers Can Delete Facebook Friends, Thanks to Flaw

#8
post #7

it's a typical programmer mistake. So how do I avoid it ?

Put some middleware into your web framework that will insert a "secret" into all forms, which contains an unforgeable token generated by the page. Only accept form input when that secret token matches the expected value.

Django will do this for you; presumably other frameworks have similar mechanisms.

http://docs.djangoproject.com/en/dev/ref/contrib/csrf/