WebApp Sec mailing list archives

Re: Session Fixation


From: "Ian" <webappsec () fishnet co uk>
Date: Tue, 01 Apr 2003 09:50:32 +0100

On 1 Apr 2003 at 0:28, HarryM wrote:

Actually, I think suggesting to anyone that they invest in half-measures
when their time can be better spent elsewhere is even more damaging. On
the
one hand, I can see your argument: it raises the bar ever so slightly,
which is a good thing. But I don't think it's a good _enough_ thing.
Consider that most people implementing these systems _aren't_ experts.
They
understand IP, they understand networking, but they don't really think
about how to break things, so relying on IP seems "good enough". Giving
the
un-informed bad choices and telling them to get it right is a receipe for
disaster if ever I've seen one.

One should never rely on IP for *anything* :-)

I agree, except to say that I wouldn't consider it "investing in half
measures" - at least, not the way I've coded it - since (a) it's one small
measure among many other precautions taken (tamper-proof cookies, detection
of scripted attacks, input validation, account lockouts, and so on) and (b),
at ~5 lines of code, it's not much of an investment!

I very much agree that it should be made known to as many people as possible
that IP, in the context of web services, is unreliable as a means of
identification, as silly as that may sound to the uninitiated, and that it
should never be depended on for anything - least of all security.

HarryM

Hi,

Has anyone put the Internet Explorer ^Super Cookie^ to use ?

For the particular app I am working on, I can guarantee that all the 
user are connecting with IE over ssl.  Plus they all (mainly) go 
through a router from the same LAN, thus appear to have the same IP.

I am currently logging the super cookie to try and determine if it 
really is unique enough.

Regards

Ian
-- 




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