From owner-freebsd-hackers@FreeBSD.ORG Tue Sep 30 15:07:32 2008 Return-Path: Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2258A10656A0 for ; Tue, 30 Sep 2008 15:07:32 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from smtp.infracaninophile.co.uk (gate6.infracaninophile.co.uk [IPv6:2001:8b0:151:1::1]) by mx1.freebsd.org (Postfix) with ESMTP id 8B2C08FC29 for ; Tue, 30 Sep 2008 15:07:31 +0000 (UTC) (envelope-from m.seaman@infracaninophile.co.uk) Received: from lack-of-gravitas.thebunker.net (gateway.ash.thebunker.net [213.129.64.4]) (authenticated bits=0) by smtp.infracaninophile.co.uk (8.14.3/8.14.3) with ESMTP id m8UF7Nj1038775 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 30 Sep 2008 16:07:24 +0100 (BST) (envelope-from m.seaman@infracaninophile.co.uk) X-DKIM: Sendmail DKIM Filter v2.7.2 smtp.infracaninophile.co.uk m8UF7Nj1038775 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=infracaninophile.co.uk; s=200708; t=1222787244; bh=ulnw4iyPlO5yma JQhSKFwFOh86Lnox8W8Miej5zystA=; h=Message-ID:Date:From:MIME-Version: To:Subject:References:In-Reply-To:Content-Type: Content-Transfer-Encoding:Cc:Content-Type:Date:From:In-Reply-To: Message-ID:Mime-Version:References:To; z=Message-ID:=20<48E240AB.9 040802@infracaninophile.co.uk>|Date:=20Tue,=2030=20Sep=202008=2016: 07:23=20+0100|From:=20Matthew=20Seaman=20|Organization:=20Infracaninophile|User-Agent:=20Thunderbird= 202.0.0.16=20(X11/20080811)|MIME-Version:=201.0|To:=20freebsd-hacke rs@freebsd.org,=20roberto@keltia.freenix.fr|Subject:=20Re:=20SSH=20 Brute=20Force=20attempts|References:=20<200809301401.m8UE1QDm039930 @lurza.secnetix.de>|In-Reply-To:=20<200809301401.m8UE1QDm039930@lur za.secnetix.de>|X-Enigmail-Version:=200.95.6|Content-Type:=20text/p lain=3B=20charset=3DUTF-8=3B=20format=3Dflowed|Content-Transfer-Enc oding:=207bit; b=gVEaGT1z6H+771N2i1AnVurdKOxwzcNiIFCrog0O33vg+gcrIp fXRMxF2IfcHVm8Bbtou0vcQst//43zgNSsno7Ud3hk2fD4n6croPl9vLP3RAH7MCpNh o5NBWfDk647twaGxtGZ/RJkQLCDaufV6qdRKs8jeY0MpjtJjA7ZNQY= Message-ID: <48E240AB.9040802@infracaninophile.co.uk> Date: Tue, 30 Sep 2008 16:07:23 +0100 From: Matthew Seaman Organization: Infracaninophile User-Agent: Thunderbird 2.0.0.16 (X11/20080811) MIME-Version: 1.0 To: freebsd-hackers@freebsd.org, roberto@keltia.freenix.fr References: <200809301401.m8UE1QDm039930@lurza.secnetix.de> In-Reply-To: <200809301401.m8UE1QDm039930@lurza.secnetix.de> X-Enigmail-Version: 0.95.6 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.0 (smtp.infracaninophile.co.uk [81.187.76.162]); Tue, 30 Sep 2008 16:07:24 +0100 (BST) X-Virus-Scanned: ClamAV 0.94/8359/Tue Sep 30 14:29:02 2008 on happy-idiot-talk.infracaninophile.co.uk X-Virus-Status: Clean X-Spam-Status: No, score=-2.6 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VERIFIED,SPF_FAIL autolearn=no version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on happy-idiot-talk.infracaninophile.co.uk Cc: Subject: Re: SSH Brute Force attempts X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Sep 2008 15:07:32 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: RIPEMD160 Oliver Fromme wrote: | Ollivier Robert <> wrote: | > According to Henrik Hudson: | > > Yeap, -security | > > | > > However, also try this in pf.conf (specific rules related to this; you'll need | > > more for a real pf.conf): | > > | > > table { } persist | > > block in quick from | > > pass in on $ext_if proto tcp from any to ($ext_if) port ssh keep state | > > (max-src-conn 5, max-src-conn-rate 4/300, overload flush global) | > | > That one is very effective. | | It's especially effective to enable to DoS you. | An attacker simply has to spoof the source address | on SYN packets, which is trivial. :-( Adding a whitelist of ssh addresses that should never be blocked is equally trivial.... But, like the perl folk say: TIMTOWTDI. Cheers, Matthew - -- Dr Matthew J Seaman MA, D.Phil. Flat 3 ~ 7 Priory Courtyard PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate ~ Kent, CT11 9PW, UK -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEAREDAAYFAkjiQKsACgkQ3jDkPpsZ+VbzsgCfY64vNfuMhRrGRYgK4rDawWq4 xDwAnRMXY54hiooKCFBp7U/SxILUsxsa =yQm5 -----END PGP SIGNATURE-----