Re: Adding a simple editor to the base system

[Arnaud Lacombe <lacombar%gmail.com@localhost>]

On Thu, Feb 12, 2009 at 11:48 AM, D'Arcy J.M. Cain <darcy%druid.net@localhost> 
wrote:
> ------------ File: /usr/bin/edit -----------
> #! /bin/sh
> exec ${EDITOR:-/usr/bin/vi}
> --------------------------------------------
>
This looks like the "alternatives" sub-system Debian had for at least
14years[0], except that your proposal can be exploited very easily:
 1) make ${EDITOR} point to an evil binary
 2) make the user become root (using su(1))
 3) tell him to edit a file
 4) evil 1 - user 0

 - Arnaud

[0]: not less if I trust the copyright notice of `/usr/sbin/update-alternatives'