Security problems with sudo

[John Tapsell]

Hey all,

  Many of you will probably remember the fun that was had over the
.desktop files problem.  Well there was a second issue that was
brought up at the time by the same guy
(http://www.geekzone.co.nz/foobar/6229), but seems to have been
silently dropped.

  The problem is if you ever run sudo (or graphical equivalent) as a
normal user then its trivial for another program to exploit that and
silently become root.  There are dozens of ways to do this, but
ultimately the problem is simply that you need to elevate prillages in
an untrusted environment.

  A very simple example would be a simple bash script that ran 'ps'
and watched for 'kdesu' to be run.  Then ran 'kdesu mybadprogram'
immediately after.  It would then be run without the user knowing.

  Now the question is..  is there any way to protected against this?
The best that I can think of is having a special shortcut that only
the kernel can see (like ctrl+alt+del in windows) then have the kernel
draw a text prompt directly on the framebuffer etc.  Urgh, it gets
uglier the more I think about.

  Can this be solved at all?

John