Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 7 Dec 2000 12:33:38 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 7 Dec 2000 12:33:28 -0500 Received: from brutus.conectiva.com.br ([200.250.58.146]:40693 "EHLO morcego.distro.conectiva") by vger.kernel.org with ESMTP id ; Thu, 7 Dec 2000 12:33:15 -0500 Date: Thu, 7 Dec 2000 15:02:47 -0200 From: "Rodrigo Barbosa (aka morcego)" To: linux-kernel@vger.kernel.org, riel@conectiva.com.br Subject: [whitevampire@MINDLESS.COM: Naptha - New DoS] Message-ID: <20001207150247.G24723@conectiva.com.br> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="O8XZ+2Hy8Kj8wLPZ" Content-Disposition: inline User-Agent: Mutt/1.2.5i X-GeekCode-Version: 3.1 X-GeekCode: CS/IT$ d- s+: a-->- C++++(++) UL++++ P--- L+++(++++)$ E--- W+(++) N+(++) o K? w--- O- M- V PS+ PE++ Y+(++) PGP++(+++) t+>++ 5+(++) X+ R++(*) tv+ b+++ DI++++ D+ G++ e h* r++ y+++ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org --O8XZ+2Hy8Kj8wLPZ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable I'm just forwarding it. I know nothing about it. I don't know how it works. I don't know how to protect agains it. I don't know what is a Kernel. I don't know what is Linux. I don't know what is e-mail. Who am I ?=20 Where am I ? What are all those green dots in the sky ? Ahhhhhhhhhhhh :-) Anyway, I talked to Riel before sending this bug here, and he acknoledged that it's really something new: hummmm indeed, this is a new one which hits in the tcp ESTABLISHED phase ----- Forwarded message from White Vampire ----- Date: Wed, 6 Dec 2000 23:34:39 -0500 From: White Vampire Subject: Naptha - New DoS Greetings, [ Misc Info ] I find it rather odd that this has yet to be mentioned on Bugtraq. I know of more than one person besides myself who has experienced some problems with this DoS since this advisory was released. I delayed mentioning it on this list because I figured someone from Razor would release it, or someone who was involved with the discovery. Various vendors are no doubt already coding like mad. I have disabled Keepalive in Apache (via 'Keepalive Off' in the configuration file) and changed the kernel timeouts, as recommended by the advisory. This will help some, but not enough. I hope to see complete fixes available soon, perhaps this will help kick-start it. Limiting public access to TCP daemons is also a way to help prevent attacks. [ Quick Summary ] Basically, it will leave a TCP connection on the target machine in a "certain state." The method discovered will exhaust resources on the target machine, whereas the originating machine will not be=20 affected that greatly. Before such attacks were infeasible because the originating machine would also be affected. The target machine can be starved of resources to the point of failure. Some affected operating systems: * Novell's Netware 5.0 with sp1 (Will not recover) * Linux (2.2.x .. others ?) (Unknown.. can recover sometimes?) * FreeBSD 4.0-REL (Can recover in short period) * Possibly others.. it is a rather widespread problem. Unaffected operating systems: * OpenBSD seems to be unaffected * Windows 2000 seems to be unaffected For more information on NAPTHA visit: http://razor.bindview.com/publish/advisories/adv_NAPTHA.html [ Credit and Disclaimer ] An advisory was released by Razor on November 30th. I had not involvement with the discovery or release of this advisory. This e-Mail is simply a summary to help system administrators and other individuals who are interested or are experiencing problems learn about the attack. I shared my experiences and summarized some information from the advisory. I am just sharing the information. Good luck to the vendors, and good luck to the rest of the world. I sure have not had a fun time resulting these attacks. Regards, --=20 __ ______ ____ / \ / \ \ / / White Vampire\Rem \ \/\/ /\ Y / http://www.gammagear.com/ (Gear for the BOFH) \ / \ / http://www.webfringe.com/ \__/\ / \___/ http://www.gammaforce.org/ \/ "Silly hacker, root is for administrators." ----- End forwarded message ----- --=20 Rodrigo Barbosa (morcego) - rodrigob@conectiva.com.br Conectiva R&D Team - http://distro.conectiva.com.br "Quis custodiet custodes?" - http://www.conectiva.com --O8XZ+2Hy8Kj8wLPZ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE6L8K3n5NdOMMM/nERAgRnAKDT7u5TC3yOicohTBDzJyLBzBDgQQCg5S6D xt9xJxsUED1RlNse7ogrHtc= =4wJd -----END PGP SIGNATURE----- --O8XZ+2Hy8Kj8wLPZ-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/