From owner-freebsd-security@FreeBSD.ORG Mon Aug 4 15:35:13 2003 Return-Path: Delivered-To: freebsd-security@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 07D9C37B401 for ; Mon, 4 Aug 2003 15:35:13 -0700 (PDT) Received: from gw.celabo.org (gw.celabo.org [208.42.49.153]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3FA5943F93 for ; Mon, 4 Aug 2003 15:35:12 -0700 (PDT) (envelope-from nectar@celabo.org) Received: from madman.celabo.org (madman.celabo.org [10.0.1.111]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "madman.celabo.org", Issuer "celabo.org CA" (verified OK)) by gw.celabo.org (Postfix) with ESMTP id 8FDF354846 for ; Mon, 4 Aug 2003 17:35:11 -0500 (CDT) Received: by madman.celabo.org (Postfix, from userid 1001) id 2D4766D455; Mon, 4 Aug 2003 17:35:11 -0500 (CDT) Date: Mon, 4 Aug 2003 17:35:11 -0500 From: "Jacques A. Vidrine" To: freebsd-security@FreeBSD.org Message-ID: <20030804223511.GC11083@madman.celabo.org> Mail-Followup-To: "Jacques A. Vidrine" , freebsd-security@FreeBSD.org References: <200308040004.h7404VVL030671@freefall.freebsd.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200308040004.h7404VVL030671@freefall.freebsd.org> X-Url: http://www.celabo.org/ User-Agent: Mutt/1.5.4i-ja.1 Subject: IMPORTANT FOR lukemftpd USERS (was Re: FreeBSD Security Advisory FreeBSD-SA-03:08.realpath) X-BeenThere: freebsd-security@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Security issues [members-only posting] List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Aug 2003 22:35:13 -0000 On Sun, Aug 03, 2003 at 05:04:31PM -0700, FreeBSD Security Advisories wrote: > (1) lukemftpd(8), an alternative FTP server: realpath(3) is used to > process the MLST and MLSD commands. [lukemftpd(8) is not built or > installed by default.] [...] > the realpath(3) vulnerability may be > exploitable, leading to arbitrary code execution with the privileges > of the authenticated user. This is probably only of concern on > otherwise `closed' servers, e.g. servers without shell access. [...] I have a correction to make regarding the above text. In the case of lukemftpd (and lukemftpd only), in some situations the vulnerability may be used to execute code with _superuser privileges_. If lukemftpd is NOT invoked with `-r', then it does NOT completely drop privileges when a user logs in. Thus, a successful exploit will be able to regain superuser privileges. Conversely, if lukemftpd IS invoked with `-r', then the original advisory text above applies. The example usage for lukemftpd that was in /etc/inetd.conf prior to 5.1-RELEASE included the `-r' flag, but there is no longer an example in 5.1-RELEASE. I don't think there was ever an example entry for 4.x. I would normally immediately publish a revised advisory with this additional information, however lukemftpd is neither built nor installed by default. Since that is the case, I will probably wait a few days before revision in case further useful information comes to light. Cheers, -- Jacques Vidrine . NTT/Verio SME . FreeBSD UNIX . Heimdal nectar@celabo.org . jvidrine@verio.net . nectar@freebsd.org . nectar@kth.se