Players overflow in Serious engine UDP (was Alpha Black Zero, 29 Sep 2004)

[Luigi Auriemma <aluigi () autistici org>]

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                             Luigi Auriemma

Application:  Serious engine
              http://www.seriousengine.com
Games:        all the games based on this engine and using the UDP
              protocol:
              - Alpha Black Zero
              - Nitro family
              - Serious Sam Second Encounter 1.07
Platforms:    Windows, Linux and Mac
Bug:          crash
Exploitation: remote, versus server
Date:         28 November 2004 (and 29 Sep 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
===============


The Serious engine is a well known game engine developed by Croteam
(http://www.croteam.com) and used by some games.


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2) Bug
======


The bug affects the games based on the Serious engine using the UDP
protocol (those using TCP are immune).

The problem is that the server doesn't limit the amount of new players,
so it crashs when too much (fake) players try to join.

Is needed only one packet to create a fake player and the bug can be
exploited also versus servers protected by password "without" knowing
the keyword.


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


http://aluigi.altervista.org/fakep/ssfakep.zip


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4) Fix
======


No fix.


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