Broadcast client buffer-overflow in Purge Jihad <= 2.0.1

[Luigi Auriemma <aluigi () altervista org>]

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                             Luigi Auriemma

Applications: Purge and Purge Jihad
              http://www.purgeonline.net
Versions:     Purge       <= 1.4.7
              Purge Jihad <= 2.0.1
Platforms:    Windows
Bug:          broadcast client's buffer overflow
Risk:         highly critical
Exploitation: remote, versus clients (broadcast)
Date:         16 Feb 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
===============


Purge Jihad is a game developed by Freeform Interactive using the
Lithtech Talon graphic engine:

"It is a hybrid Role-Playing-Game / First-Person-Shooter set in the
near future accounting a war between the diametrically opposed forces
of science-fiction (the Order) and fantasy (the Chosen)"


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2) Bug
======


The bug is a "broadcast" buffer-overflow affecting clients.
In fact each client that enters in the multiplayer screen automatically
contacts the master server and then sends a query to each available
online game server to know informations about the current match running
on it.

The attacker'server must simply reply to clients'requests with an
information packet containing 2 big fields: battle type and map name.
These fields in fact are managed by a vulnerable function that copies
the provided strings in a 64 bytes buffer not able to contain the
maximum size of 256 bytes of each field.


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


http://aluigi.altervista.org/poc/purge-cbof.zip


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4) Fix
======


Purge Jihad 2.0.2


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