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Message-ID: <1305133740.26856.12.camel@subarashii>
Date: Wed, 11 May 2011 19:09:00 +0200
From: phocean <0x90@...cean.net>
To: "Dobbins, Roland" <rdobbins@...or.net>
Cc: "full-disclosure@...ts.grok.org.uk" <full-disclosure@...ts.grok.org.uk>
Subject: Re: Sony: No firewall and no patches
Le mercredi 11 mai 2011 à 16:49 +0000, Dobbins, Roland a écrit :
> On May 11, 2011, at 10:03 PM, phocean wrote:
>
> > - DDoS : anyway, a firewall isn't more susceptible to DoS than the server it protects. If you look at the hardware performance of modern
> > firewalls, if an attacker has the ability to DoS it, then only a considerable server farm that very few companies can afford will be able to sustain it.
>
> My operational experience, including that acquired during my tenure working for the world's largest manufacturer of firewalls by units shipped, contradicts this statement.
Can you develop? I still don't see how the hell the typical web server
will handle as much traffic as one of these Checkpoint, Cisco or
whatever monsters.
>
> > - stateless scales badly on large networks, because it requires much more complex and lengthy rules if you are serious with security.
>
> This is a) untrue and b) a near non-sequitur. In general state is much more harmful on larger networks than on smaller ones; and there's no correlation at all between the size of a network and the complexity of network access policies.
I was talking about complexity correlation between using stateful or
stateless. Maybe it does not make any difference on a frontal firewall
with a few servers behind. But on a large network with inter-vlan
filtering, it matters a lot. Believe me, this one is based on my
operational experience.
>
> > Another advantage of stateful is that there is a first sanity check of the sessions on a specialized hardware rather than on a generic TCP/IP
> > stack of a bloated server OS.
>
> Marketing aside, those 'sanity checks' take place in software, not in hardware; and they actually constitute a greatly broadened attack surface (look at the multiple vulnerability notices/patch notices for any commercial stateful firewall you can name, as well as for open-source stateful firewall packages).
I still trust more the network stack of a Linux/BSD/IOS dedicated box
than the one of a Windows Server. And it means a crafted packet has to
go through mixed devices.
>
> > For instance, the network stack of Windows is probably much more prone to bug/crash due to poor handling of crafted packets than a dedicated
> > firewall (Checkpoint, Cisco, Fortinet...) may be.
>
> Sadly, this is also not borne out by experience. Quite the opposite, actually.
Well maybe. I have no certitude on this point, but if you have facts,
it's welcome.
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