From owner-freebsd-security Mon Jul 8 7:46: 4 2002 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 71DFF37B400 for ; Mon, 8 Jul 2002 07:46:01 -0700 (PDT) Received: from gw.catspoiler.org (217-ip-163.nccn.net [209.79.217.163]) by mx1.FreeBSD.org (Postfix) with ESMTP id E966843E31 for ; Mon, 8 Jul 2002 07:46:00 -0700 (PDT) (envelope-from dl-freebsd@catspoiler.org) Received: from mousie.catspoiler.org (mousie.catspoiler.org [192.168.101.2]) by gw.catspoiler.org (8.12.5/8.12.5) with ESMTP id g68Ejowr000591; Mon, 8 Jul 2002 07:45:54 -0700 (PDT) (envelope-from dl-freebsd@catspoiler.org) Message-Id: <200207081445.g68Ejowr000591@gw.catspoiler.org> Date: Mon, 8 Jul 2002 07:45:50 -0700 (PDT) From: Don Lewis Subject: Re: hiding OS name To: rgbrenner@myrealbox.com Cc: laurence@fluxinc.com, freebsd-security@FreeBSD.ORG In-Reply-To: <200207080834.53431.rgbrenner@myrealbox.com> MIME-Version: 1.0 Content-Type: TEXT/plain; charset=iso-8859-1 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On 8 Jul, Ramsey G. Brenner wrote: > From /sys/i386/conf/LINT > # > # TCP_DROP_SYNFIN adds support for ignoring TCP packets with SYN+FIN. This > # prevents nmap et al. from identifying the TCP/IP stack, but breaks support > # for RFC1644 extensions and is not recommended for web servers. Only until someone enhances nmap to detect this signature and identify the host as running FreeBSD with the TCP_DROP_SYNFIN option enabled. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message