Buffer-overflow in the XM loader of Cheese Tracker 0.9.9

[Luigi Auriemma <aluigi () autistici org>]

#######################################################################

                             Luigi Auriemma

Application:  Cheese Tracker
              http://reduz.com.ar/cheesetracker/
              http://sourceforge.net/projects/cheesetronic
Versions:     <= 0.9.9 and current CVS
Platforms:    *nix and others
Bug:          buffer-overflow in Loader_XM::load_instrument_internal
Exploitation: local
Date:         23 Jul 2006
Author:       Luigi Auriemma
              e-mail: aluigi () autistici org
              web:    aluigi.org


#######################################################################


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


#######################################################################

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


Cheese Tracker is a well known music tracker for the CT, IT, XM and S3M
file formats.


#######################################################################

======
2) Bug
======


The XM loader used by Cheese Tracker is affected by a buffer-overflow
vulnerability which happens when it tries to store the exceeding data
available in the input file in the junkbuster buffer of only 500 bytes.

> From cheesetracker/loaders/loader_xm.cpp:

Loader::Error Loader_XM::load_instrument_internal(Instrument *p_instr,bool p_xi,int p_cpos, int p_hsize, int p_sampnum) 
{
        ...
        if (!p_xi) {

            if ((reader.get_file_pos()-p_cpos)<p_hsize) {

                Uint8 junkbuster[500];

                //printf("extra junk XM instrument in header! hsize is %i, extra junk: 
%i\n",p_hsize,(reader.get_file_pos()-p_cpos));

                reader.get_byte_array((Uint8*)junkbuster,p_hsize-(reader.get_file_pos()-p_cpos));
            }
            ...


#######################################################################

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


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


#######################################################################

======
4) Fix
======


No fix.
No reply from the developers.


#######################################################################


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

_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/