[22633] in bugtraq
Re: Is there user Anna at your host ?
daemon@ATHENA.MIT.EDU (Tobias J. Kreidl)
Thu Sep 13 00:19:10 2001
Date: Wed, 12 Sep 2001 11:20:05 -0700 (MST)
From: "Tobias J. Kreidl" <Tobias.Kreidl@NAU.EDU>
To: bugtraq@securityfocus.com
Reply-To: "Tobias J. Kreidl" <tjk@jan.ucc.nau.edu>
Message-id: <200109121820.LAA07193@jan.ucc.nau.edu>
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Josha Bronson wrote on Wed, 12 Sep 2001 10:12:56 -0700:
> Wrong? No. Trivial? Up in the air. Enumeration of user names is
> definitely an important step in attacking a system, but just a username
> is not going to get you very much. Also, there are a number of other
> methods that could be used, like searching for '@domain.tld', VRFY in
> sendmail (as you mentioned) or good old fashion finger (yes a lot of
> people still run fingerd).
Of course, you can always send loads of email messages to a machine
and track which messages didn't bounce (hence find out which ones work).
It's not very efficient, but sending bulk email is easy and routines like
sendmail can handle thousands of small messages very efficiently.
Another alternative security measure for machines with user logins is to
put the public_html areas on a disks that are exported to the web server
and hence at least hide to some degree the actual machine on which the
login account resides.
Tobias Kreidl
NAU/ITS, academic computing
