The attacker didn't create the session though. Sverre is right.
That's why "session riding" requires getting the user to execute
arbitrary code or actions through the vehicles of phishing, luring,
or social engineering. If the attacker had created the session
a priori there wouldn't be a valid user session to be "riding".
Perhaps though you bring up another important aspect we have not
looked at: What if an attacker creates a known bad/poisoned session
and then hands that off to the user, perhaps by swaping their
good session cookie for the bad session cookie?
We could write a whole new whitepaper on this. Thoughts on names?
"Session Swapping" has illiteration, however, I am more fond of:
"Session Castling". It sounds a lot cooler and ensures one's clients
stay confused as to exactly what the heck you're really talking about.
Other options for naming abound; I'm open to suggestions:
http://thesaurus.reference.com/search?q=swap
Arian
-----Original Message-----
From: Elihu Smails [mailto:elihusmails2000@yahoo.com]
Sent: Tuesday, December 21, 2004 12:48 PM
To: Sverre H. Huseby
Cc: webappsec@securityfocus.com
Subject: Re: Whitepaper "SESSION RIDING - A Widespread
Vulnerability in Today's Web Applications"
But you have already stored the IP address of the
attacker who created the session. Therefore when the
victim connects to your web app, you do not allow them
in because the IP address does not match what is
currently stored in the session information.
--- "Sverre H. Huseby" <shh@thathost.com> wrote:
[Elihu Smails]
| Sessions should track the remote IP address of
the client at a
| minimum, so that this problem could go away.
Unfortunately, checking IP addresses won't solve the
Session Riding /
Web Trojan problem, as the request is coming from
the victim's
computer.
Sverre.
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