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Re: Yet another thread on the legality of port scanning
From: Charley Hamilton <chamilto () uci edu>
Date: Thu, 18 Mar 2004 09:36:52 -0800

> Authorized users are told they are authorized users.


> Perhaps I'm not aware of it, but is there an "authorized user/service" database on the internet? I must have missed that.

So portscanning is the generally accepted method of discovering what
services any given machine offers? And this is the way that everyone should determine whether or not there is a service being offered to them?

I was under the impression that resources (not just 'net, in general)
were private unless declared public.  Has something drasticsally changed
since I was last taught about these matters? Authorized users of the supercomputing center at UCSD are notified of their authority when they
successfully apply for an account there.  The fact that some moron leaves
a port open accepting unencrypted telnet connections and otherwise fails to properly secure the system is not an invitation for a visit. Why would you be port scanning to see if the SCC offers unencrypted telnet unless you are:

        - tasked by the SCC (or their security group) with identifying  
        - the university performing routine security screening
        - an intruder seeking access

I get that a port scan is not an attack.  I don't get why a generic user
should be portscanning.  I get that it's possible, even that it's probably
legal short of explicit notice to the contrary.
> I would argue that you're wrong. Anonymous FTP is a very frequent occurrance on the internet and it's not unreasonable to expect that CNN might have an anonymous FTP site for content. What, exactly, makes you think that it's an unreasonable service to use?

The particular choice of FTP was a poor one.  I agree that anonymous FTP
is quite common.  However, how did you find out about the anonymous FTP
sites you use (e.g. kernel.org)?  By portscanning for them?  I was able to
find gnu's ftp site without a port scan. I looked at their "front door" (website) and found out about it. It seems that if a service is intendedto be public, it will be *published*. How it is published is up to the *owner*, not
the self-declared potential user.

Assuming that my interpretation of your writing is correct,
you would support unsolicited bulk email.

> Actually, I'm not the original poster, but I'd have to say that unsolicited e-mail is just fine. I don't have a problem with people just sending me e-mail. What I have a problem with is people hacking into systems and converting them into SPAM relays.

So you support unsolicited bulk email as long as no hacking was committed
in generating it? Are you defining the act of hacking the system as creating the difference between SPAM and acceptable unsolicited bulk email? Different people, different opinions.

I will grant unsolicited email is okay.  However, unsolicited bulk email is
the electronic equivalent of unsolicited physical mail. It is a drag on the mail system (physical or electronic).

I certainly agree this discussion has drifted quite far
afield.  I don't debate the potential for *legitimate* uses of
port scans.  I just debate whether a legitimate use of
port scans as a means of generally profiling a box.  Why do you
as a random stranger need to know what services a given box offers?


Charles Hamilton, PhD EIT               Faculty Fellow
Department of Civil and                 Phone: 949.824.3752
    Environmental Engineering           FAX:   949.824.2117
University of California, Irvine        Email: chamilto () uci edu

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