[GRLUG] get back access to root

[Bob Kline]

In fact,  kubuntu live will not allow you
to mount the hard drive without being
root. How do you become root on a live
CD?

Wouldn't the procedure below allow you
to walk up to any PC with Linux on it and
make changes that only root can normally
make,  and thereby enable you to trash
someone's system,  or otherwise make
changes someone wouldn't want?

Or am I missing something here?

The original issue was changing hostname,
and then not being able to log back in to a
system as root.

    -Bob


On 9/5/06, Michael Mol <mikemol at gmail.com> wrote:
> LiveCD route:
>
> 1. Drop in an Ubuntu or KNOPPIX LiveCD
> 2. Open a terminal
> 3. Mount the hard drive
> 4. Modify /etc/hosts and /etc/hostname
> 5. Unmount the hard drive
> 6. Reboot
>
> On 9/5/06, Bob Kline <bob.kline at gmail.com> wrote:
> > Thanks.  I'll try that.  What's the LiveCD route?
> >
> >    -Bob
> >
> >
> > On 9/5/06, Michael Mol <mikemol at gmail.com> wrote:
> > > Hm.  Well, there's the generic Linux root exploit, if you don't want
> > > to go the LiveCD route.  (Though the LiveCD route is easier, IMO)
> > >
> > > Add the following to your kernel command line when you see the grub boot menu:
> > > init=/bin/sh
> > >
> > > Next, remount your root filesystem so that you can write to it:
> > > mount -o remount,rw /
> > >
> > > Then modify your host and hosts file as necessary:
> > > /usr/bin/vi /etc/hosts
> > > /usr/bin/vi /etc/hostname
> > >
> > > Now remount your root filesystem as read-only (to save your changes to it):
> > > mount -o remount,ro /
> > >
> > > Finally, power off your computer. (The halt and shutdown commands
> > > won't work; They depend on init or xinit, which isn't running.  Just
> > > hold the power button in for at least four seconds.)
> > >
> > > On 9/5/06, Bob Kline <bob.kline at gmail.com> wrote:
> > > > Step two is the problem:  su.
> > > >
> > > > I can't get in as root. I can log in
> > > > as myself fine.
> > > >
> > > >    -Bob
> > > >
> > > >
> > > > On 9/5/06, bfdamkoehler at worldnet.att.net <bfdamkoehler at worldnet.att.net> wrote:
> > > > >
> > > > > I don't know your level of knowledge, so forgive me this is too
> > > > > detailed. I assume that your problem is caused by the new hostname not
> > > > > being /etc/hosts. Its seems like that might affect X windows but
> > > > > "shouldn't" bother any non-X apps.
> > > > >
> > > > >     * login to your non-priv account
> > > > >     * su
> > > > >     * cd /etc
> > > > >     * cp -v hosts hosts.save # make sure you have a saved copy in case
> > > > >       of problems
> > > > >     * vim hosts
> > > > >           o shift o
> > > > >           o newhostname nnn.nnn.nnn.nnn (replace newhostname with your
> > > > >             new hostname and nnn.nnn.nnn.nnn with the IP address of your
> > > > >             machine)
> > > > >           o hit the ESC key and then type :wq
> > > > >
> > > > > That "should" fix it, but you will still have the old hostname for your
> > > > > machine in /etc/hosts as well, which won't hurt anything. You can tell
> > > > > if its working by typing "ping newhostname" unless you have a firewall
> > > > > that blocks ping packets.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Michael Mol wrote:
> > > > >
> > > > > >Did you check that /etc/hosts and /etc/hostname is sane?
> > > > > >If not, can you fix them using sudo and vim?
> > > > > >
> > > > > >If you can't use sudo et al, try booting off of a livecd and edit the
> > > > > >files that way.
> > > > > >
> > > > > >On 9/4/06, Bob Kline <bob.kline at gmail.com> wrote:
> > > > > >
> > > > > >
> > > > > >>* used hostname to change,  well,  the host name.
> > > > > >>
> > > > > >>*  now cannot get back in as root.  I get a message
> > > > > >>   saying something like gethostbyname() doesn't work.
> > > > > >>
> > > > > >>What have I done to my self?   Is there a way to get
> > > > > >>back in as root,  or have I found a way of locking myself
> > > > > >>out of the system now?
> > > > > >>
> > > > > >>I won't even get in to why I tried to do this.......  :-(
> > > > > >>
> > > > > >>More tales of  the amateur.
> > > > > >>
> > > > > >>    -Bob
> > > > > >>_______________________________________________
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> > > > > >>
> > > > > >>
> > > > > >>
> > > > > >
> > > > > >
> > > > > >
> > > > > >
> > > > >
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