Date: Sat, 19 Dec 1998 17:19:34 +0200
From: Philip Stoev <philip@EINET.BG>
Reply-To: Bugtraq List <BUGTRAQ@netspace.org>
To: BUGTRAQ@netspace.org
Subject: ValueClick CGI Vulnerability

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The ValueClick Online Advertising agency web interface has a CGI
vulnerability that allows easy username/password capture without using
sniffing software.

When you go to ValueClick home page (www.valueclick.com) and log on, your
username and password are embedded in the URL and if you subsequently leave
their site and go somewhere else, this URL will end up in this site's HTTP
refferer log which I beleive is a serious fault because one can easily not
just garble with your account, but also redirect any cheques you are about
to receive from ValueClick to himself.

ValueClick was notified several months ago and they responded they will
substitute GET with POST in their CGI, but they have taken no such action.

Sincerely,

Philip Stoev

-- Free SAT & TOEFL preparation softwate @ http://studywiz.hypermart.net
This message was sent by Philip Stoev (philip@einet.bg)
tel: (359 2) 715949, 9549488 fax: (359 2) 544669

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Date: Sat, 19 Dec 1998 19:57:20 -0500
From: "Ellen (ValueClick)" <ellen@VALUECLICK.COM>
Reply-To: Bugtraq List <BUGTRAQ@netspace.org>
To: BUGTRAQ@netspace.org
Subject: ValueClick

Hi,

Please allow me to introduce myself.  My name is Ellen O'Rourke and I am
Host Member Manager for ValueClick.

I would like to refer to the letter you wrote BUGTRAQ@NETSPACE.ORG
regarding "ValueClcik vernerability."

Let me explain:

If the user decides to go to another site after they
are logged in,  either via a bookmark or typing in
a url, the referring url will be blank.  If we had
a link to the outside, the referring url would
contain the logged in user's username and password.

The links that we do have to the outside, such
as on the exclude banners page where a user
can click on a banner to view the advertiser's
site, have the referring url stripped off to
protect the host's login info.

If you have evidence that contradicts this, we would very much appreciate
your advising us.

We appreciate your interest in ValueClick.

---------------------------------------------------------
                   Ellen O'Rourke
Member Site Manager                ellen@valueclick.com
                     ValueClick
        The pay-for-results advertising network!

ValueClick Banner Ad Network       http://www.valueclick.com


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Date: Sat, 19 Dec 1998 18:47:56 -0800
From: Trev <trev@KICS.BC.CA>
Reply-To: Bugtraq List <BUGTRAQ@netspace.org>
To: BUGTRAQ@netspace.org
Subject: Re: ValueClick

Hi Ellen

Perhaps you haven't heard of the Brumleve cache bug, or the other various
ways remote websites can gather the information in your browser's history.
It is so simple to use POST instead of GET... I don't see why you want to
take the chance of it being intercepted.  There are a number of ways that
requested URLs can be logged etc.

Trev