From owner-freebsd-security Wed Mar 21 23:34:51 2001 Delivered-To: freebsd-security@freebsd.org Received: from mailhost01.reflexnet.net (mailhost01.reflexnet.net [64.6.192.82]) by hub.freebsd.org (Postfix) with ESMTP id 6427C37B71E for ; Wed, 21 Mar 2001 23:34:39 -0800 (PST) (envelope-from cjc@rfx-216-196-73-168.users.reflexcom.com) Received: from rfx-216-196-73-168.users.reflexcom.com ([216.196.73.168]) by mailhost01.reflexnet.net with Microsoft SMTPSVC(5.5.1877.197.19); Wed, 21 Mar 2001 23:32:35 -0800 Received: (from cjc@localhost) by rfx-216-196-73-168.users.reflexcom.com (8.11.3/8.11.1) id f2M7YWX58258; Wed, 21 Mar 2001 23:34:32 -0800 (PST) (envelope-from cjc) Date: Wed, 21 Mar 2001 23:34:31 -0800 From: "Crist J. Clark" To: "J.A. Terranson" Cc: security@FreeBSD.ORG Subject: Re: chflags/symlinks Message-ID: <20010321233431.C574@cjc-desktop.users.reflexcom.com> Reply-To: cjclark@alum.mit.edu References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from measl@mfn.org on Tue, Mar 20, 2001 at 05:57:23AM -0600 Sender: owner-freebsd-security@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Tue, Mar 20, 2001 at 05:57:23AM -0600, J.A. Terranson wrote: > > Good Morning/Afternoon/Etc., > > I believe there is an issue WRT the above pair. The chflags(1) manpage says, Symbolic links do not have flags, so unless the -H or -L option is set, chflags on a symbolic link always succeeds and has no effect. > Problem: There is no way to secure (schg, etc) the link. I can > secure the files to which they point, but not the links > themselves. Theoretically, an attack can be launched by deleting the > symlinks and creating new ones, rather than altering the files directly > (as they are safe under securelevel 3). > > For us, the issue has been nighty cleanup routines killing the > symlinks, and thereby breaking *everything* :-( > > > I there is something I have missed here, I would *love* to know... You can schg the directory in which the symlinks are in. That of course may or may not be practical for you. -- Crist J. Clark cjclark@alum.mit.edu To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-security" in the body of the message