RE: Session Hijacking over HTTP

[tclahr () br ibm com]

yeah! another comment. The user could be using a NAT address to access the 
Internet, and the attacker could be accessing the internet from the same 
network. In this case the IP verification would be useless since both 
would be reaching the webserver using the same IP address.

Obrigado / Regards

/*
 * Thiago Canozzo Lahr; CEH; LPIC-1;
 * Vulnerability Assessment Specialist;
 * IBM ITDelivery Brazil - Security & Risk Management;
 * Phone: +55 19 2132-7091;
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From:
"Shenk, Jerry A" <jshenk () decommunications com>
To:
"Serg B" <sergeslists () gmail com>, "11ack3r" <11ack3r () gmail com>
Cc:
<pen-test () securityfocus com>
Date:
19/03/2008 16:29
Subject:
RE: Session Hijacking over HTTP



Sometimes, tying an http session to an IP address will incorrectly kick
users out who are going through proxies.  AOL traffic causes this at
times by switching proxies.  Since HTTP is a protocol that makes lots of
different connections, the browser can easily (but not often) change IP
addresses during a session. 

The fact that each HTTP connection is a different IP session makes using
ports in the session management a problem too....in fact, I don't see
how that would work at all.

-----Original Message-----
From: listbounce () securityfocus com [mailto:listbounce () securityfocus com]
On Behalf Of Serg B
Sent: Tuesday, March 18, 2008 6:42 PM
To: 11ack3r
Cc: pen-test () securityfocus com
Subject: Re: Session Hijacking over HTTP

To protect session cookies you can set the cookie property: to send
only over SSL.  Also, regenerate SID after the user has authenticated
to the application - this will safe guard their account in case the
SID was compromised prior to authentication.  The SID itself should be
custom generated and include a digest of the following client
properties (can be more, this is the minimum): IP address, port
number, agent string.  This way a session will be tied to a particular
machine and user. This is the industry best practice.

Don't worry about building "custom browser or enterprise solution"
since it will only complicate things and get you hacked, remember the
KISS principle.  This is of course excluding the fact that it sounds
like a complete bandaid solution to a problem that should be solved at
design or implementation stage of the SDLC. In regards to the "trusted
channel" - SSL is about as trusted a it gets (excluding my uber army
of specially trained carrier pidgins of course).

Serg


On Tue, Mar 18, 2008 at 10:21 PM, 11ack3r <11ack3r () gmail com> wrote:
> Hello Everyone,
>
>  I was curious to know how would webmail portals like gmail.com and
>  yahoo.com protect their users from session hijacking when they use
>  HTTP after authentication.
>
>  As I see it is trivial to capture traffic over the wire including
>  session cookies. In such a case can an attacker just reuse the
session
>  cookies in his/her browser and compromise the user account?
>
>  WHat is the best way to protect session cookies from hijacking esp.
>  due to network eavesdropping? Of course HTTPS can also be bypassed
>  with MITM attacks if users ignore browser warnings.
>
>  Looking forward to some knowledge here.
>
>  Cheers!!
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