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Re: making Debian secure by default

From Franco Martelli <martellif67@gmail.com>
Newsgroups linux.debian.user
Subject Re: making Debian secure by default
Date 2024-03-28 17:30 +0100
Message-ID <In0Nz-2juy-5@gated-at.bofh.it> (permalink)
References <ImJa1-27aa-1@gated-at.bofh.it> <ImVNT-2fvh-15@gated-at.bofh.it>
Organization linux.* mail to news gateway

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On 28/03/24 at 12:05, Marc SCHAEFER wrote:
> Hello,
> 
> On Wed, Mar 27, 2024 at 05:30:50PM -0400, Lee wrote:
>> Apparently the root of the security issue is that wall is a setguid program?
> 
> a) wall must be able to write to your tty, which is not possible
>     if wall is not installed setguid OR if people have sane permissions
>     on their terminals (e.g. set to mesg n)
> 
> b) in addition, for this exploit to run, command-not-found must be
>     started with the not found command as argument: in the two Debian
>     releases I just tried (buster and bookworm), with bash,
>     command-not-found was not installed.
> 
> The idea of the exploit is that you get a prompt for entering a sudo
> password, which is a simple text (which gets more convincing because
> of a recently introduced bug in wall which does not filter out terminal
> escape / control sequences), then you type the root password, which
> is presumably not the name of an existing command, so command-not-found
> PASSWORD is run, and someone on another terminal and user can do
> a ps to see that password argument if he is quick or polling.
> 
> To fix this:
> 
> a) don't type a root password / sudo password unless you know that
>     it should happen
> 
> b) don't allow others to write on your terminals, in particular
>     if you run priviledged commands and expect sudo prompts
> 
> c) patch wall so that its texts are always shown to be
>     different from other program outputs (== filter out
>     anything else than printable characters)
> 
>         THIS IS MY PREFERRED WORKAROUND :)
>         (mixing controls (prompts) and data is always
>          a very bad idea)
> 
> d) don't have other users on your machine / use containers.

Do you know whether it exists a tutorial/wiki that explain how to avoid 
users in favor to containers?

Thanks in advance

-- 
Franco Martelli

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making Debian secure by default Lee <ler762@gmail.com> - 2024-03-27 22:40 +0100
  Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 00:10 +0100
    Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 05:30 +0100
      Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 14:40 +0100
        Re: making Debian secure by default Greg Wooledge <greg@wooledge.org> - 2024-03-28 16:30 +0100
          Re: making Debian secure by default Hans <hans.ullrich@loop.de> - 2024-03-28 16:50 +0100
            Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 19:20 +0100
              Re: making Debian secure by default Ralph Aichinger <ra@h5.or.at> - 2024-03-29 08:50 +0100
              Re: making Debian secure by default Stefan Monnier <monnier@iro.umontreal.ca> - 2024-03-29 20:10 +0100
              Re: making Debian secure by default Jeffrey Walton <noloader@gmail.com> - 2024-03-29 20:40 +0100
          Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 17:00 +0100
            Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 21:20 +0100
          Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-28 18:50 +0100
            Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 20:40 +0100
            Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-29 18:00 +0100
              Re: making Debian secure by default Joe <joe@jretrading.com> - 2024-03-29 18:30 +0100
                Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-29 18:50 +0100
                Re: making Debian secure by default Nicholas Geovanis <nickgeovanis@gmail.com> - 2024-04-01 02:30 +0200
                Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-04-01 03:50 +0200
                Re: making Debian secure by default Roberto C. Sánchez <roberto@debian.org> - 2024-04-01 05:00 +0200
                Re: making Debian secure by default Nate Bargmann <n0nb@n0nb.us> - 2024-04-01 10:40 +0200
                Re: making Debian secure by default <tomas@tuxteam.de> - 2024-04-06 09:50 +0200
                Re: making Debian secure by default Nate Bargmann <n0nb@n0nb.us> - 2024-04-06 09:50 +0200
                Re: making Debian secure by default <tomas@tuxteam.de> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default <tomas@tuxteam.de> - 2024-04-06 09:50 +0200
                Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-04-06 09:50 +0200
                Re: making Debian secure by default Nate Bargmann <n0nb@n0nb.us> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default Jeffrey Walton <noloader@gmail.com> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default Nate Bargmann <n0nb@n0nb.us> - 2024-04-06 09:52 +0200
                Re: making Debian secure by default Charles Curley <charlescurley@charlescurley.com> - 2024-04-06 09:52 +0200
                Re: making Debian secure by default Jeffrey Walton <noloader@gmail.com> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default John Hasler <john@sugarbit.com> - 2024-04-06 09:51 +0200
                Re: making Debian secure by default Joe <joe@jretrading.com> - 2024-04-06 09:52 +0200
                Re: making Debian secure by default John Hasler <john@sugarbit.com> - 2024-04-06 09:52 +0200
                Re: making Debian secure by default Joe <joe@jretrading.com> - 2024-04-06 09:52 +0200
              Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-29 18:50 +0100
                Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-29 21:00 +0100
                Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-30 17:10 +0100
          Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 19:10 +0100
            Re: making Debian secure by default Jeffrey Walton <noloader@gmail.com> - 2024-03-28 23:20 +0100
    Re: making Debian secure by default Florent Rougon <f.rougon@free.fr> - 2024-03-28 17:30 +0100
      Re: making Debian secure by default Florent Rougon <f.rougon@free.fr> - 2024-03-28 18:10 +0100
      Re: making Debian secure by default Greg Wooledge <greg@wooledge.org> - 2024-03-28 18:10 +0100
        Re: making Debian secure by default Florent Rougon <f.rougon@free.fr> - 2024-03-28 18:10 +0100
  Re: making Debian secure by default jeremy ardley <jeremy.ardley@gmail.com> - 2024-03-28 00:40 +0100
    Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 00:50 +0100
      Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 05:50 +0100
  Re: making Debian secure by default <tomas@tuxteam.de> - 2024-03-28 06:20 +0100
    Re: making Debian secure by default Emanuel Berg <incal@dataswamp.org> - 2024-03-28 06:30 +0100
      Re: making Debian secure by default <tomas@tuxteam.de> - 2024-03-28 08:20 +0100
      Re: making Debian secure by default Michael Kjörling <2695bd53d63c@ewoof.net> - 2024-03-28 12:20 +0100
        Re: making Debian secure by default Emanuel Berg <incal@dataswamp.org> - 2024-03-28 12:40 +0100
          Re: making Debian secure by default David Wright <deblis@lionunicorn.co.uk> - 2024-03-28 21:40 +0100
            Re: making Debian secure by default Emanuel Berg <incal@dataswamp.org> - 2024-03-29 10:40 +0100
              Re: making Debian secure by default David Wright <deblis@lionunicorn.co.uk> - 2024-03-30 04:00 +0100
    Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-28 15:50 +0100
    Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 17:30 +0100
      Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 18:10 +0100
        Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 21:50 +0100
      Re: making Debian secure by default tomas@tuxteam.de - 2024-03-28 18:30 +0100
        Re: making Debian secure by default Lee <ler762@gmail.com> - 2024-03-28 20:30 +0100
          Re: making Debian secure by default Greg Wooledge <greg@wooledge.org> - 2024-03-28 20:30 +0100
            Re: making Debian secure by default Michael Kjörling <2695bd53d63c@ewoof.net> - 2024-03-28 21:50 +0100
          Re: making Debian secure by default tomas@tuxteam.de - 2024-03-28 21:20 +0100
            Re: making Debian secure by default Curt <curty@free.fr> - 2024-03-29 17:10 +0100
              Re: making Debian secure by default debian-user@howorth.org.uk - 2024-03-29 21:50 +0100
    Re: making Debian secure by default debian-user@howorth.org.uk - 2024-03-28 22:50 +0100
  Re: making Debian secure by default Marc SCHAEFER <schaefer@alphanet.ch> - 2024-03-28 12:10 +0100
    Re: making Debian secure by default Franco Martelli <martellif67@gmail.com> - 2024-03-28 17:30 +0100
    Re: making Debian secure by default Michel Verdier <mv524@free.fr> - 2024-03-28 17:30 +0100
      Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-28 17:40 +0100
  Re: making Debian secure by default Michael Kjörling <2695bd53d63c@ewoof.net> - 2024-03-28 21:50 +0100
  Re: making Debian secure by default Richmond <dnomhcir@gmx.com> - 2024-03-28 21:50 +0100
  Re: making Debian secure by default Jeffrey Walton <noloader@gmail.com> - 2024-03-29 16:40 +0100
  Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-31 21:10 +0200
    Re: making Debian secure by default Roberto C. Sánchez <roberto@debian.org> - 2024-03-31 21:30 +0200
      Re: making Debian secure by default gene heskett <gheskett@shentel.net> - 2024-03-31 22:30 +0200
        Re: making Debian secure by default Andy Smith <andy@strugglers.net> - 2024-03-31 23:20 +0200
          Re: making Debian secure by default gene heskett <gheskett@shentel.net> - 2024-04-01 01:00 +0200

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