From owner-freebsd-security@FreeBSD.ORG Wed Mar 26 06:33:20 2014 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 3AFF132F for ; Wed, 26 Mar 2014 06:33:20 +0000 (UTC) Received: from hergotha.csail.mit.edu (wollman-1-pt.tunnel.tserv4.nyc4.ipv6.he.net [IPv6:2001:470:1f06:ccb::2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id CDB11DFF for ; Wed, 26 Mar 2014 06:33:19 +0000 (UTC) Received: from hergotha.csail.mit.edu (localhost [127.0.0.1]) by hergotha.csail.mit.edu (8.14.7/8.14.7) with ESMTP id s2Q6XFnb068355; Wed, 26 Mar 2014 02:33:17 -0400 (EDT) (envelope-from wollman@hergotha.csail.mit.edu) Received: (from wollman@localhost) by hergotha.csail.mit.edu (8.14.7/8.14.4/Submit) id s2Q6XF5m068352; Wed, 26 Mar 2014 02:33:15 -0400 (EDT) (envelope-from wollman) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <21298.29867.672397.320969@hergotha.csail.mit.edu> Date: Wed, 26 Mar 2014 02:33:15 -0400 From: Garrett Wollman To: Kimmo Paasiala Subject: Re: NTP security hole CVE-2013-5211? (Gary Palmer) In-Reply-To: References: X-Mailer: VM 7.17 under 21.4 (patch 22) "Instant Classic" XEmacs Lucid X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.4.3 (hergotha.csail.mit.edu [127.0.0.1]); Wed, 26 Mar 2014 02:33:17 -0400 (EDT) X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED autolearn=disabled version=3.3.2 X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on hergotha.csail.mit.edu X-Mailman-Approved-At: Wed, 26 Mar 2014 11:34:03 +0000 Cc: freebsd-security@freebsd.org X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: "Security issues \[members-only posting\]" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Mar 2014 06:33:20 -0000 < said: > I believe Gary was talking about changing the control/status port > and not the actual service port (UDP 123). That should be doable > without breaking compatibility with existing NTP tools. NTP does not have a separate "control/status port"; all NTP operations that could be called "control" and "status" use the NTP protocol and the NTP port. If you configure your NTP server correctly (or start from a good default configuration), these operations will be restricted using NTP's built-in authentication and access-control mechanisms. In NTP-speak, the relevant packets are known as "mode 6" and "mode 7" messages. ntpq and ntpdc, since they run as non-root, will obviously use an ephemeral source port. Historically (not sure if it's still true), ntpd would generate a random key on startup and then fork a process to read the configuration file and handle DNS resolution; the child process would then use mode 7 messages to add associations in the main server process as each host name was resolved. -GAWollman