Messages in this thread | | | Date | Mon, 13 Jan 2003 11:06:40 -0700 (MST) | From | Dax Kelson <> | Subject | Re: [PATCH] Secure user authentication for NFS using RPCSEC_GSS [0/6] |
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On Mon, 13 Jan 2003, Paul Jakma wrote:
> 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.).
Well, I was trying to keep my email short. Yes, if you login to a compromised machine, and then obtain krbv5 credentails the evil root user can access/delete/modify your files stored on a RPSEC_GSS NFS server.
With RPSEC_GSS, a compromised machine, on it's own (no logged in users except evil root), can not access/delete/modify files stored on the NFS home directory server, which is quite different than the normal case. This helps when the exploit-of-the-day hits at 4am Saturday morning.
As a matter of practice you shouldn't leave cached credentials lying around when you not logged in. Unless you have a very strong reason not to, kill your ssh-agent and run kdestory on logout (.bash_logout and friends).
Dax
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