Ghost users in Chat Anywhere 2.72

[Luigi Auriemma <aluigi () altervista org>]

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                             Luigi Auriemma

Application:  Chat Anywhere
              http://www.lionmax.com/chatanywhere.htm
Versions:     <= 2.72
Platforms:    Windows
Bug:          users cannot be banned or kicked
Risk:         low
Exploitation: remote, via browser
Date:         09 Mar 2004
Author:       Luigi Auriemma
              e-mail: aluigi () altervista org
              web:    http://aluigi.altervista.org


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1) Introduction
2) Bug
3) The Code
4) Fix


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===============
1) Introduction
===============


Chat Anywhere is a web chat server allowing multiple chat rooms
accessible via browser. It supports also remote administration via web.


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2) Bug
======


Using %00 before the nickname the user is able to hide himself to the
administrator.
Practically the admin cannot see the user's IP address in the
administration web page because it is substituited by the text $IP$.
This problem avoids the banning and the kicking of the user so the
admin has no control over him.


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===========
3) The Code
===========


I have created a simple html file that sends %00 in plain-text because
almost all the browsers sends it encoded as %2500:

  http://aluigi.altervista.org/poc/ca-ghost.htm


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4) Fix
======


Version 2.72a


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--- 
Luigi Auriemma
http://aluigi.altervista.org