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From: lang@panews
Newsgroups: comp.sys.next
Subject: Re: SLIP from next.com
Message-ID: <1991Feb20.211000.19474@ibmpa.awdpa.ibm.com>
Date: 20 Feb 91 21:10:00 GMT
References: <5240@media-lab.MEDIA.MIT.EDU> <3191@unccvax.uncc.edu> <1991Feb19.231809.24359@engin.umich.edu>
Sender: news@ibmpa.awdpa.ibm.com (news id)
Reply-To: lang@ibmpa.awdpa.ibm.com (Lang Zerner)
Followup-To: alt.flame
Organization: IBM AWD  Palo Alto
Lines: 43

In article <5240@media-lab.MEDIA.MIT.EDU>, lacsap@plethora.media.mit.edu (Pascal Chesnais) writes:
> Next does not publically list any of its machines as anonymous
> ftp archive servers for the internet.  If they have a security
> hole, I do not exploit it even though I know it exists.

Anonymous ftp access is not a security "hole".  It is enabled by several
deliberate steps on the part of the system administrator.  The
instructions for enabling the anonymous ftp feature are very clear about
the possibility of security problems and explain, step by step, how to
avoid them.  From the ftpd(8) man page:

     4)   If the user name is ``anonymous'' or ``ftp'', an
          anonymous ftp account must be present in the password
          file (user ``ftp'').  In this case the user is allowed
          to log in by specifying any password...

     In the last case, ftpd takes special measures to restrict
     the client's access privileges.  The server performs a
     chroot(2) command to the home directory of the ``ftp'' user.
     In order that system security is not breached, it is recom-
     mended that the ``ftp'' subtree be constructed with care:

chroot makes it impossible for the anonymous ftp user to access any file
not placed in the ~ftp directory.  The page ends with a section
including the following crystal-clear warning:

     The anonymous account is inherently dangerous and should
     avoided when possible.

Anonymous ftp can only be enable by a deliberate choice of the system
administrator.  She cannot enable the feature without creating a special
directory for anonymously accessible files.  

It is simpler for a system administrator to create a password-protected
"friends" account for a select group.  If you wish to opine as to why a
system administrator would go to the trouble of setting up anonymous ftp
if she did not wish the files to be accessible to all, please do so, but
try to find a more appropriate newsgroup in which to do so.  I would be
more than happy to join you in alt.flame, to which followups have been
redirected. :-)

Be seeing you...
++Lang