#######################################################################
Luigi Auriemma
Application: Liero Xtreme
http://lieroxtreme.thegaminguniverse.com
Versions: <= 0.62b
Platforms: Windows
Bugs: A] server crash/freeze
B] format string in the visualization function
Exploitation: A] remote, versus server
B] local/remote, versus clients
Date: 06 Mar 2006
Author: Luigi Auriemma
e-mail: [email protected]
web: http://aluigi.altervista.org
#######################################################################
1) Introduction
2) Bugs
3) The Code
4) Fix
#######################################################################
Liero Xtreme (aka Lierox) is a freeware clone of the classic DOS game
called Liero, and is mainly focused on the possibility of expanding and
customizing the game through mods, levels and skins.
Both LAN and Internet multiplayer (through the master server) are
supported.
#######################################################################
The server can be easily crashed or freezed using a long string with
the "connect" command.
The problem is caused by the instructions used by the game for handling
the data of this command which in some cases lead to the immediate
crash of the server or a loop which freezes the game.
The client's function which visualizes the messages on the screen
(0x004052d0) is affected by a format string vulnerability which can be
used to execute malicious code.
Exist different ways for exploiting this bug but the most interesting
are the following:
#######################################################################
http://aluigi.altervista.org/poc/lieroxxx.zip
For the bug B my proof-of-concept exploits only the first method I have
explained, for the other two is enough to:
#######################################################################
No fix.
No reply from the developers.
#######################################################################
Luigi Auriemma
http://aluigi.altervista.org