From owner-freebsd-questions@FreeBSD.ORG Tue Sep 15 12:27:52 2009 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id B7BE2106568B for ; Tue, 15 Sep 2009 12:27:52 +0000 (UTC) (envelope-from mail25@bzerk.org) Received: from ei.bzerk.org (tunnel490.ipv6.xs4all.nl [IPv6:2001:888:10:1ea::2]) by mx1.freebsd.org (Postfix) with ESMTP id 413D68FC12 for ; Tue, 15 Sep 2009 12:27:52 +0000 (UTC) Received: from ei.bzerk.org (BOFH@localhost [127.0.0.1]) by ei.bzerk.org (8.14.2/8.14.2) with ESMTP id n8FCRk5r027888; Tue, 15 Sep 2009 14:27:46 +0200 (CEST) (envelope-from mail25@bzerk.org) Received: (from bulk@localhost) by ei.bzerk.org (8.14.2/8.14.2/Submit) id n8FCRkWi027887; Tue, 15 Sep 2009 14:27:46 +0200 (CEST) (envelope-from mail25@bzerk.org) Date: Tue, 15 Sep 2009 14:27:46 +0200 From: Ruben de Groot To: Freminlins Message-ID: <20090915122746.GA27732@ei.bzerk.org> Mail-Followup-To: Ruben de Groot , Freminlins , utisoft@gmail.com, FreeBSD Questions References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-4.4 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 autolearn=ham version=3.2.5 X-Spam-Checker-Version: SpamAssassin 3.2.5 (2008-06-10) on ei.bzerk.org X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0.1 (ei.bzerk.org [127.0.0.1]); Tue, 15 Sep 2009 14:27:50 +0200 (CEST) Cc: FreeBSD Questions , utisoft@gmail.com Subject: Re: Non-root user and accept() or listen() X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 15 Sep 2009 12:27:52 -0000 On Tue, Sep 15, 2009 at 11:39:05AM +0100, Freminlins typed: > 2009/9/14 Chris Rees > > > > > Isn't this a bit drastic? Listening sockets are opened by very many > > types of processes, as well as remembering that sendmail, BIND, and > > others don't actually run as root... I suppose it'd be possible, but > > would it actually be useful? > > > > Sure, those open listening sockets. But those are things I want to listen. > > Now suppose a user account was hacked, and "Bob" sets up a web server > listening on some random port above 1024. If "Bob" couldn't use listen() he > wouldn't be able to do that. Haven't tried it, but you can probably set net.inet.ip.portrange.reservedhigh to 65535. That way only root can bind(2) to any port. Ruben