From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <14ec7b180802221023j472a7953v70c31da9ed1c0563@mail.gmail.com>
Date: Fri, 22 Feb 2008 11:23:57 -0700
From: "andrey mirtchovski" <mirtchovski@gmail.com>
To: "Fans of the OS Plan 9 from Bell Labs" <9fans@cse.psu.edu>
Subject: Re: [9fans] a challenge
In-Reply-To: <13426df10802220953q3af4a1aarf93acaaebfedc9b@mail.gmail.com>
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well, i checked the source. turns out bash 3.2 drops privileges if uid
!= euid and requires the -p flag to allow itself to run in setuid
mode:

$ cp /bin/bash .
$ sudo chown root bash
$ sudo chmod 4755 bash
$ ./bash -p
# id
uid=500(andrey) gid=500(andrey) euid=0(root) groups=500(andrey)
# whoami
root
#

that doesn't make me like Plan 9 any less, you know :)

On Fri, Feb 22, 2008 at 10:53 AM, ron minnich <rminnich@gmail.com> wrote:
> here is a challenge. I realize it's linux but I think this is the
>  right group to ask anyway; I think you'll appreciate the humor in it.
>  So far few I have talked to have gotten it.
>
>  There is a file, called /bin/bash.
>
>  You are allowed to do this as root.
>  cp this file to /tmp. Do something to it to make it so that, when you
>  are not root, you can run the file in /tmp and get a root shell.
>
>  Don't assume the obvious. And please don't post "that's trivial" until
>  you have actually done it.
>
>  ron
>