Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 26 Jun 2000 22:20:30 -0600 (MDT)
From:      Nate Williams <nate@yogotech.com>
To:        David Nugent <davidn@blaze.net.au>
Cc:        Nate Williams <nate@yogotech.com>, freebsd-security@FreeBSD.ORG
Subject:   Re: Fwd: WuFTPD: Providing *remote* root since at least1994
Message-ID:  <200006270420.WAA01672@nomad.yogotech.com>
In-Reply-To: <Pine.BSF.4.21.0006271102300.7433-100000@biscuit.mel.ausisp.net>
References:  <200006261555.JAA18584@nomad.yogotech.com> <Pine.BSF.4.21.0006271102300.7433-100000@biscuit.mel.ausisp.net>

next in thread | previous in thread | raw e-mail | index | archive | help
> > > > 2) The ability to create a upload directory where files are
> > > >    automatically chown/chmod'd to a different user, so that
> > > >    it can't be used as a warez site.
> > > 
> > > Removing visibility of the directory is the classic solution to this, but
> > > obviously this is a "security by obscurity" technique, and therefore
> > > wrong.
> > 
> > It's not wrong, and it's not obscurity.
> 
> 'wrong' is perhaps too strong, 'not ideal' is better. But this is
> a case of obscurity.
> 
> > It's making those files 'unavailable', since there is no other type of
> > solution.
> 
> The point is, I guess, that since the uid that put them there can also get
> it from there, all that is missing is the ability to view what's there,
> so the files are "available", just not advertised as such.

Actually, no.  Note what I wrote above.  It's both chmod/chown'd so that
the uploading user can't touch them.  They can't over-write them or do
anything to modify them once they've been uploaded.

> > How else would you make 'uploaded' files unavailable?
> 
> Permissions and ownership of course, as you originally suggested. The
> ability to configure the mode on uploaded file modes as 000 without
> changing ownership would not be effective unless chmod was denied for the
> directory (which you can't do without removing writability or coding
> around it). Otherwise a change of owner is required. Visibility or not of
> the directory then becomes an administrative option rather than the only
> means by which files may be 'protected'.

See above.  The change of owner is done.


Nate


To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200006270420.WAA01672>