From: Stephen Hemminger <shemminger@osdl.org>
To: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] OpenBSD Networking-related randomization port
Date: Fri, 28 Jan 2005 10:18:25 -0800 [thread overview]
Message-ID: <20050128101825.388990a0@dxpl.pdx.osdl.net> (raw)
In-Reply-To: 1106934475.3778.98.camel@localhost.localdomain
On Fri, 28 Jan 2005 18:47:55 +0100
Lorenzo Hernández García-Hierro <lorenzo@gnu.org> wrote:
> El vie, 28-01-2005 a las 18:40 +0100, Adrian Bunk escribió:
> > On Fri, Jan 28, 2005 at 06:17:17PM +0100, Lorenzo Hernández García-Hierro wrote:
> > >...
> > > As it's impact is minimal (in performance and development/maintenance
> > > terms), I recommend to merge it, as it gives a basic prevention for the
> > > so-called system fingerprinting (which is used most by "kids" to know
> > > how old and insecure could be a target system, many time used as the
> > > first, even only-one, data to decide if attack or not the target host)
> > > among other things.
> > >...
> >
> > "basic prevention"?
> > I hardly see how this patch makes OS fingerprinting by e.g. Nmap
> > impossible.
>
> That's an example, as you can find at the grsecurity handbook [1]:
>
> "The default Linux TCP/IP-stack has some properties that make it more
> vulnerable to prediction-based hacks. By randomizing several items,
> predicting the behaviour will be a lot more difficult."
No it just changes the fingerprint table. "Hmm, this looks like a
newer generation system, must be OpenBSD or Linux".
> "Randomized IP IDs hinders OS fingerprinting and will keep your machine
> from being a bounce for an untraceable portscan."
>
> References:
> [1]: http://www.gentoo.org/proj/en/hardened/grsecurity.xml
This is a very transitory effect, it works only because your machine
is then different from the typical Linux machine; therefore the scanner
will go on to the next obvious ones. But if this gets incorporated widely
then the rarity factor goes away and this defense becomes useless.
--
Stephen Hemminger <shemminger@osdl.org>
next prev parent reply other threads:[~2005-01-28 18:18 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-01-28 17:17 [PATCH] OpenBSD Networking-related randomization port Lorenzo Hernández García-Hierro
2005-01-28 17:40 ` Adrian Bunk
2005-01-28 17:47 ` Lorenzo Hernández García-Hierro
2005-01-28 18:18 ` Stephen Hemminger [this message]
2005-01-28 18:54 ` Lorenzo Hernández García-Hierro
2005-01-28 19:09 ` Adrian Bunk
2005-01-28 18:02 ` Stephen Hemminger
2005-01-28 18:31 ` Lorenzo Hernández García-Hierro
2005-01-28 18:52 ` Stephen Hemminger
2005-01-28 18:58 ` Lorenzo Hernández García-Hierro
2005-01-28 20:34 ` Lorenzo Hernández García-Hierro
2005-01-28 20:45 ` David S. Miller
2005-01-28 21:34 ` Stephen Hemminger
2005-01-28 21:45 ` David S. Miller
2005-01-29 6:59 ` Andi Kleen
2005-01-28 20:47 ` Arjan van de Ven
2005-01-28 22:12 ` Lorenzo Hernández García-Hierro
2005-01-29 8:04 ` Arjan van de Ven
2005-01-29 8:05 ` Arjan van de Ven
2005-01-29 9:15 ` Valdis.Kletnieks
2005-01-31 16:50 ` Adrian Bunk
2005-01-31 17:23 ` Lorenzo Hernández García-Hierro
2005-01-31 20:11 ` Ingo Molnar
2005-01-31 23:27 ` linux
2005-02-12 22:29 ` Andi Kleen
2005-02-12 23:25 ` linux
2005-02-13 0:18 ` Roland Dreier
2005-02-13 1:41 ` linux
2005-02-02 17:17 ` linux
2005-02-02 17:38 ` Lorenzo Hernández García-Hierro
2005-02-03 19:51 ` Stephen Hemminger
2005-02-03 20:14 ` Lennert Buytenhek
2005-01-31 19:42 ` Valdis.Kletnieks
2005-01-31 20:03 ` Lorenzo Hernández García-Hierro
2005-02-01 23:22 ` Matt Mackall
2005-01-28 18:04 ` Jörn Engel
2005-01-28 18:07 ` Arjan van de Ven
2005-01-28 18:36 ` Lorenzo Hernández García-Hierro
2005-02-01 14:54 ` Bill Davidsen
2005-01-28 19:24 ` Horst von Brand
2005-01-29 18:16 ` Florian Weimer
2005-01-28 19:24 Hank Leininger
2005-01-29 7:24 linux
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