Re: RE: [Xen-devel] severe security issue on dom0/xend/xm/non-root users

[Kurt Garloff <kurt@xxxxxxxxxx>]

Hi Ian,

On Sun, Mar 13, 2005 at 05:17:38PM -0000, Ian Pratt wrote:
> I think this is a good first step, and pretty easy to implement.

... if you know twisted well enough. I did not invest much time,
but I failed.

I had a short look and thought that adding something like

    def connectionMade(self):
       if self.transport:
           log.info("xend: connect from host %s, port %ui" % \
                       (self.transport.client[0], self.transport.client[1]))
           if self.transport.client[1] >= 1024:
               self.loseConnection()

to class EventProtocol in SrvDaemon.py would do the job.

I was wrong ... the log.info never even triggered.

Making this configurable would be a plus as well, I guess.
in XendRoot.py, I had put

    """Default for xend-privileged """
    xend_privileged_default   = '1'

[...]
    def get_xend_privileged(self):
       """Get the setting that controls whether xend only accepts connections
       from privileged ports.
       """
       return self.get_config_value('xend-privileged', 
self.xend_privileged_default)


And then these pieces would need to be connected.
And xm taught to try grabbing a privileged port.

> Volunteers?

Someone more familiar with the xend implementation should be more
successful than me.

> With the next generation of tools we could insist on using SSL and thus
> that the client have an appropriate certificate.

That's the full blown approach, of course, as it would enable you to
allow remote control.

Regards,
-- 
Kurt Garloff                   <kurt@xxxxxxxxxx>             [Koeln, DE]
Physics:Plasma modeling <garloff@xxxxxxxxxxxxxxxxxxx> [TU Eindhoven, NL]
Linux: SUSE Labs (Director)    <garloff@xxxxxxx>            [Novell Inc]

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