Re: Facebook URL Redirect Vulnerability

[Chris Evans <scarybeasts () gmail com>]

On Wed, Mar 2, 2011 at 6:30 AM, Nathan Power <np () securitypentest com> wrote:

> There are 3 different steps to perform an attack using a URL redirect:  1)
> trick the user


You do not need an open redirect to trick the user. Try <a href="
http://www.evil.com";>
www.facebook.com/OMFGacatvomitingacanaryandpuppiesandshit</a>

Also, a lot of the open redirector debate hinges on assuming a user knows
how to parse an URL and validate a hostname. It's a false assumption.

Cheers
Chris


> 2) redirect 3) exploit .. We are using a Facebook URL to trick the user, we
> are using the URL redirect as the catalyst to perform an exploit.
>
> Here are some examples of the types of attacks you can perform with a URL
> redirect, CSRF, phishing (fake fb login), and browser exploits (javascript
> zombie,0days,etc).
>
> How would you have written the impact section?
>
> To be clear - I was trying to make a point when determining the impact,
> once you click on a bad link, bad things will happen.
>
>
>
> Nathan Power
> www.securitypentest.com
>
>
>
> On Tue, Mar 1, 2011 at 8:56 PM, Andrew Farmer <andfarm () gmail com> wrote:
>
> > On 2011-02-28, at 09:42, Nathan Power wrote:
> > > 3. Impact:
> > >
> > > Potentially allow an attacker to compromise a victim’s Facebook account
> > > and/or computer system.
> >
> > Do you have an actual attack in mind which could accomplish either of
> > these goals, or is this wishful thinking? (Browser exploits don't really
> > count, as those would work just fine with or without the redirect.)
> >
> > To be clear - open redirects are certainly a problem, but don't try to
> > call them any more than that.
>
>
>
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