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Re: Cross Site Identification (CSID) attack. Description and demonstration.
From: Benji <me () b3nji com>
Date: Wed, 13 Jan 2010 16:47:54 +0000

yes, but scarier BECAUSE IT INVOLVES FACEBOOK ARGH!

On Wed, Jan 13, 2010 at 4:45 PM, Christian Sciberras <uuf6429 () gmail com>wrote:

I'm confused, isn't this just like XSRF (cross-site request forgery)?

Regards,
Chris.


On Wed, Jan 13, 2010 at 4:33 PM, Ronen Z <ronen () quaji com> wrote:
Hi,

A new type of vulnerability is described in which publicly available
information from social network sites obtained out of context, can be
used
to identify a user in cases where anonymity is taken for granted.

This attack (dubbed Cross Site Identification, or CSID) assumes the
following scenario: A user that is currently logged on to her social
network
account visits a 3rd party site, supposedly anonymously, in another
browser
tab. The 3rd party site causes her browser to contact the social network
site and exploit the vulnerability resulting in her identity being
disclosed
to the attacker. The 3rd party target site is not necessarily controlled
by
the attacker. It could also be, for example, any site allowing user
provided
content that includes an image link (basically any forum or blog site).
Other possibilities exist.

While the information that is received by the attacker is technically
publicly available, obtaining it in this manner effectively lifts the
veil
of anonymity from the user when interacting with the 3rd party site.

Three social networks were tested and all were found to contain the
vulnerability. These are Facebook, Orkut and Bebo. Some of the
vulnerabilities were design flaws. The vulnerabilities are described and
demonstrated. The sites were contacted in advance yet some of the
vulnerabilities are still open.

CSID is not bound only to social network sites but might be found on any
site that authenticates its users. Various flavors of the attack are
discussed.


The post below contains a detailed description of the attack and its
implications. It also includes details about the live vulnerabilities
found.

Post/White Paper:
http://blog.quaji.com/2009/12/out-of-context-information-disclosure.html




Ronen Zilberman
http://quaji.com



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_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/

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