From owner-freebsd-i386@FreeBSD.ORG Sun May 29 23:20:12 2011 Return-Path: Delivered-To: freebsd-i386@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 349461065672 for ; Sun, 29 May 2011 23:20:12 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [IPv6:2001:4f8:fff6::28]) by mx1.freebsd.org (Postfix) with ESMTP id E9DBB8FC18 for ; Sun, 29 May 2011 23:20:10 +0000 (UTC) Received: from freefall.freebsd.org (localhost [127.0.0.1]) by freefall.freebsd.org (8.14.4/8.14.4) with ESMTP id p4TNKA0Q064640 for ; Sun, 29 May 2011 23:20:10 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.14.4/8.14.4/Submit) id p4TNKAWr064639; Sun, 29 May 2011 23:20:10 GMT (envelope-from gnats) Resent-Date: Sun, 29 May 2011 23:20:10 GMT Resent-Message-Id: <201105292320.p4TNKAWr064639@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-i386@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, Sam Bowne Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 71BC81065672 for ; Sun, 29 May 2011 23:13:04 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from red.freebsd.org (red.freebsd.org [IPv6:2001:4f8:fff6::22]) by mx1.freebsd.org (Postfix) with ESMTP id 6285E8FC14 for ; Sun, 29 May 2011 23:13:04 +0000 (UTC) Received: from red.freebsd.org (localhost [127.0.0.1]) by red.freebsd.org (8.14.4/8.14.4) with ESMTP id p4TND4hC082491 for ; Sun, 29 May 2011 23:13:04 GMT (envelope-from nobody@red.freebsd.org) Received: (from nobody@localhost) by red.freebsd.org (8.14.4/8.14.4/Submit) id p4TND4EE082484; Sun, 29 May 2011 23:13:04 GMT (envelope-from nobody) Message-Id: <201105292313.p4TND4EE082484@red.freebsd.org> Date: Sun, 29 May 2011 23:13:04 GMT From: Sam Bowne To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.1 Cc: Subject: i386/157410: IPv6 Router Advertisements Cause Excessive CPU Use X-BeenThere: freebsd-i386@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: I386-specific issues for FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 29 May 2011 23:20:12 -0000 >Number: 157410 >Category: i386 >Synopsis: IPv6 Router Advertisements Cause Excessive CPU Use >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-i386 >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun May 29 23:20:10 UTC 2011 >Closed-Date: >Last-Modified: >Originator: Sam Bowne >Release: FreeBSD 8.2 >Organization: City College San Francisco >Environment: FreeBSD .localdomain 8.2-RELEASE FreeBSD 8.2-RELEASE #0: Fri Feb 18 02:24:46 UTC 2011 root@almeida.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC i386 >Description: IPv6 Router Advertisement packets cause a denial of service by CPU consumption. This is a known vulnerability in Windows systems, and it works against FreeBSD too. Here is a screen captures of the attack in action, with a slow attack of 100 packets per second: http://samsclass.info/ipv6/proj/FreeBSD-100RAps.png Here is a detailed vulnerability report I wrote about the Windows version: http://samsclass.info/ipv6/proj/flood-router6a.htm Thanks to ty Justin Hohner for telling me about this. >How-To-Repeat: To reproduce it, use Linux and the thc-ipv6 tools from http://www.thc.org/thc-ipv6/ If you run ./flood_router6 eth0 on the attacker, a FreeBSD network on the same LAN will freeze. >Fix: Mac OS X and Ubuntu Linux are not vulnerable, because they ignore all RAs after the first ten or so. >Release-Note: >Audit-Trail: >Unformatted: