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                         Luigi Auriemma

Application: Skulltag
http://www.skulltag.com
Versions: <= 0.97d-beta4.1
Platforms: Windows and Linux
Bug: heap-overflow
Exploitation: remote, versus server
Date: 23 Aug 2007
Author: Luigi Auriemma
e-mail: [email protected]
web: aluigi.org

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

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1) Introduction

Skulltag is a well known and played Doom engine mainly based on Zdoom
(but not open source as it) and focused on online gaming.

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2) Bug

The game is vulnerable to a heap overflow located in the function which
performs the huffman decompression of the incoming packets, allowing
possible malicious code execution through a single UDP packet.

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3) The Code

http://aluigi.org/poc/skulltaghof.zip

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4) Fix

No fix.
Developers have not been contacted since one year ago the format string
vulnerability I reported to them was handled as a normal bug and the
patch was released some months after my advisory.

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Luigi Auriemma
http://aluigi.org
http://mirror.aluigi.org