How secure is UNIX? (Re: Stupid man pages)

Andy DeFaria defaria at hpclapd.HP.COM
Sat Jun 9 02:18:07 AEST 1990


>/ hpclapd:comp.unix.questions / jik at athena.mit.edu (Jonathan I. Kamens) /  2:46 pm  Jun  6, 1990 /
>In article <720015 at hpclapd.HP.COM>, defaria at hpclapd.HP.COM (Andy
>DeFaria) writes:
>|> I'm no security guru on Unix but  it seems to  me that the  way around this
>|> problem  would  be to remove  this silly  restriction  and  allow  ftp (and
>|> others?) to send encrypted passwords to the other host.
>
>  I thought I already explained this.  Sigh.
>
>  Let's assume that what you said is possible.  In that case, I do the
>following:
>
>1. Log into your machine.
>2. Grab the encrypted password for root out of the (publicly readable)
                                                     ^^^^^^^^^^^^^^^^^
>   /etc/passwd.
>3. "Ftp localhost".
>4. Use username "root", and the encrypted password I've already snarfed.
>
>Presto, I've just ftp'd as root, without ever knowing the root password!
>
>  There is a fundamental concept you're missing -- the act of encrypting
>the password and comparing it to the password in /etc/passwd is the
>authentication; if you don't do the encryption, you haven't proven anything.
>
>  (How many times am I going to have to explain this?)
>
>Jonathan Kamens			              USnail:
>MIT Project Athena				11 Ashford Terrace
>jik at Athena.MIT.EDU				Allston, MA  02134
>Office: 617-253-8495			      Home: 617-782-0710
>----------

I  thought I explained  this.  IMHO  /etc/passwd should  NOT   be  publicly
readable.   If this were  true then you   couldn't ftp as  root because you
wouldn't even know the encrypted password, which, IMHO, you  shouldn't have
access to.



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