Re: gtk+ security hole.

[Rob Mosher <rmosher@xxxxxxxxxxxxx>]

A simple fix to this would be to drop priveleges before calling
gtk_init(), another easy fix is to modify gtk itself, to do this you
need to make the following modification of gtkmain.c.  In gtk-1.2.8 its
at approximately line 215, you have:

  env_string = getenv ("GTK_MODULES");

add the following line above it:
  if(geteuid() != getuid())

This will prevent gtk from loading modules if the program calling
gtk_init has a different euid than the uid.

Chris Sharp wrote:

> while going through a quick audit of gtk i found:
>
> gtk+ can be tricked into running arbitrary code
> via a bogus module.  this means any program using
> gtk that is set*id can be exploited via this
> method.  here is an exploit i wrote for this
> security hole:
>
>
> original xgtk.c(working/un-wrapped):
> http://realhalo.org/xgtk.c
[snip]

--
Rob Mosher
Lead Programmer / Systems Engineer
Lightning Internet Services, LLC