Re: NIS with local root

From: Kevin Jackson (kevin.jackson@genaware.com)
Date: 01/31/03 

Date: Fri, 31 Jan 2003 19:24:48 -0000 (GMT)
From: "Kevin Jackson" <kevin.jackson@genaware.com>
To: <focus-linux@securityfocus.com>

If you mean from "if they have physical access to the box and are
determined, they'll get root anyway" you mean exploit some unpatched
service on the system -- then you may aswell forget about and type of NFS
"squash" option altogether! ...as we are in a different territory now.
See other securityfocus.com mailing lists on that one! ;-)

The "sqash" options solves alot of problems, but to answer the first
question fully (as opposed to my half-assed original!) then securing the
network and utilising some other type of NFS/Directory service is the
answer.

NFS/NIS _or_ Security. AFAIK, its always been the two options.

The problem in the first place was to stop normal users su'ing to root and
then being able to write files. Solved by root_squash.
But then of course, that person can su - user and then write files.

So the problem really resolves around a way of protecting root on the
local system AND still provide NFS-like mounting of remote directories.
These aren't answered by using NIS and NFS alone.

Kev

> In addition to the other examples people have given, think of a lab
> environment where untrusted users aren't given root... but of course, if
> they have physical access to the box and are determined, they'll get
> root anyway. I think this discussion is helpful; too many people think
> root squashing solves more problems than it really does.
> 

-- 
Kevin Jackson
Systems Administrator                        Locate, Enquire, Empower
GenaWare Limited                              www.genaware.com
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