From owner-freebsd-security  Fri Aug 28 22:37:28 1998
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Date: Fri, 28 Aug 1998 22:30:44 -0700 (PDT)
From: scex <scex@dqc.org>
To: "Jan B. Koum " <jkb@best.com>
cc: "Jeffrey J. Mountin" <jeff-ml@mountin.net>, security@FreeBSD.ORG
Subject: Re: Shell history 
In-Reply-To: <Pine.BSF.4.02A.9808282208110.17138-100000@shell6.ba.best.com>
Message-ID: <Pine.BSF.4.02.9808282218130.29890-100000@dqc.org>
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> >>	Once can just "cp" the executable.

> >But in order to 'cp' you must be able to read.

> >Why have more permissions than needed?

> 	Uhm.. I don't have to read. If I want to execute something and it
> is in my path, I just "cp `which vi` ./..." and then "./..."

> 	Taking away read permissions from directories such as /bin, /sbin
> and etc. is just security through obscurity IMHO unless you are doing some
> other things such as trusted path execution, chroot'ed environment, etc.

[scex@twist] [~]$ cd bin
[scex@twist] [bin]$ ll bash
-rwx------  1 scex  users  - 389120 Aug 20 03:31 bash*
[scex@twist] [bin]$ chmod 711 bash
[scex@twist] [bin]$ ll bash
-rwx--x--x  1 scex users   - 389120 Aug 20 03:31 bash*
[scex@twist] [bin]$ su nobody
Password:
[nobody@twist] [bin]$ cp bash /tmp/...
cp: bash: permission denied

no-one's talking about taking away read permissions from directories
(although that also has its applications); you have to have read
permission on a file to be able to copy it (unless you fancy mucking
around in /proc & streams).

scex


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