From owner-freebsd-security Sun Feb 24 15: 5:42 2002 Delivered-To: freebsd-security@freebsd.org Received: from rwcrmhc52.attbi.com (rwcrmhc52.attbi.com [216.148.227.88]) by hub.freebsd.org (Postfix) with ESMTP id 1DF3C37B404 for ; Sun, 24 Feb 2002 15:05:38 -0800 (PST) Received: from blossom.cjclark.org ([12.234.91.48]) by rwcrmhc52.attbi.com (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020224230537.EYBX1147.rwcrmhc52.attbi.com@blossom.cjclark.org>; Sun, 24 Feb 2002 23:05:37 +0000 Received: (from cjc@localhost) by blossom.cjclark.org (8.11.6/8.11.6) id g1ON5XB15591; Sun, 24 Feb 2002 15:05:33 -0800 (PST) (envelope-from cjc) Date: Sun, 24 Feb 2002 15:05:33 -0800 From: "Crist J. Clark" To: Matt Piechota Cc: Ralph Huntington , freebsd-security@FreeBSD.ORG Subject: Re: Couple of concerns with default rc.firewall Message-ID: <20020224150533.C83869@blossom.cjclark.org> References: <20020224104008.H14963-100000@mohegan.mohawk.net> <20020224110246.M17449-100000@cithaeron.argolis.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: <20020224110246.M17449-100000@cithaeron.argolis.org>; from piechota@argolis.org on Sun, Feb 24, 2002 at 11:08:20AM -0500 X-URL: http://people.freebsd.org/~cjc/ Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Sun, Feb 24, 2002 at 11:08:20AM -0500, Matt Piechota wrote: > On Sun, 24 Feb 2002, Ralph Huntington wrote: > > > Maybe I'm missing the point, but doesn't "deny ip from any to any" (which > > is the last rule in a block-all-by-default firewall) doesn't that mean to > > block everything, meaning everything? Nothing would be allowed, not any > > icmp of any type or anything else. In order to allow anything in > > particular, that would have to be explicitly enabled in a prior (ipfw) > > rule, is that not correct? > > I think the question is did the FreeBSD team intentionally (for the > reasons of security) make the default install non-compliant with some > RFCs (read: broken), or was it just not thought of? Pretty much any kind of firewalling makes a system non-compliant. For example, not returning a RST on any TCP port not in the LISTEN state breaks the Standard. What's the first thing people do when firewalling a host? Block incoming TCP so it doesn't generate RSTs. -- Crist J. Clark | cjclark@alum.mit.edu | cjclark@jhu.edu http://people.freebsd.org/~cjc/ | cjc@freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message