From: Trond Myklebust Subject: Re: [PATCH] Secure user authentication for NFS using RPCSEC_GSS [0/6] Date: Mon, 13 Jan 2003 13:09:21 +0100 Sender: linux-kernel-owner@vger.kernel.org Message-ID: <15906.44145.47417.934888@charged.uio.no> References: <1042437391.1677.8.camel@thud> Reply-To: trond.myklebust@fys.uio.no Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Dax Kelson , Linux Kernel , NFS maillist Return-path: To: Paul Jakma In-Reply-To: List-ID: >>>>> " " == Paul Jakma writes: > On 12 Jan 2003, Dax Kelson wrote: >> Standard NFS security/authentication sucks rocks. Without this >> NFS home directory servers are just waiting to be ransacked by >> a rouge (or compromised) root user on a client machine. > AIUI, A root user still can. The users krbv5 credentials will > generally have been cached to storage. (though i suppose one > could mount that storage via NFS and use root_squash, but > that's little protection.). Once the root account has been compromised, it is 'Game Over' no matter what you do. Kerberos or no Kerberos, the simplest way to steal your identity is simply for the attacker to listen in on your tty while you are typing your password. The RPCSEC_GSS security model is not meant to protect you against root monitoring. It is meant to prevent some third party (on another machine for instance) from spoofing RPC requests in you name (== strong authentication), intercepting valid RPC requests and modifying the payload (== cryptographic data integrity checking), or listening in on the client/server communication (== data privacy). Cheers, Trond