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Re: Cisco, haven't we learned anything? (technician reset)y
From: "Steven M. Bellovin" <smb () cs columbia edu>
Date: Thu, 12 Jan 2006 21:56:01 -0500
In message <20060113023430.GI22251 () catastrophe net>, eric writes:
On Thu, 2006-01-12 at 21:05:52 -0500, Steven M. Bellovin proclaimed...
How much entropy is there in a such a serial number? Little enough
that it can be brute-forced by someone who knows the pattern? Using
some function of the serial number and a vendor-known secret key is
better -- until, of course, that "secret" leaks. (Anyone remember how
telephone credit card number verification worked before they could do
full real-time validation? The Phone Company took a 10-digit phone
number and calculated four extra digits, based on that year's secret.
Guess how well that secret was kept....)
I believe the Netscreen default password of a serial number can only be
entered over the console (and possibly modem/aux) port(s).
That works for me. But note William Leibzon's issue:
That works too and is most secure way.
But its often enough that small offices would not have person who can fix
the system and its not always possible to get network guy to come in right
a way. It is good for those cases to be able to ask somebody onsite to just
look at the back and dictate the serial# by phone.
If you have physical access, the root password matters a lot less (and
if it's the serial number, the local attacker can just peer at the
back). If you need secure remote access -- well, it's not easy with
clueless local administrators. But there's much less excuse for
clueless developers, like the ones who created the login/password pair
that started this thread -- credentials that, according to one posting,
are acceptable for remote access.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb
Re: Cisco, haven't we learned anything? (technician reset) Gadi Evron (Jan 12)
Re: Cisco, haven't we learned anything? (technician reset) Fergie (Jan 12)
- Re: Cisco, haven't we learned anything? (technician reset), (continued)