Subject: Re: [vserver] vserver security
From: Giovanni Di Stasi <gdistasi@gmail.com>
Date: Fri, 16 May 2008 00:25:07 +0200

Il Friday 16 May 2008 00:19:38 Oliver Welter ha scritto:
> Hi Giovanni,
>
> | If a have a service running in a vserver, and this service get
>
> compromised by
>
> | an attacker, is the attacker confined to the vserver, so that he/she
>
> can't
>
> | compromise any of the other services (running in other vservers), and
>
> he/she
>
> | can't modify files outside the filesystem of the compromised vserver?
>
> A user inside the vserver has access to the filesystem and the processes
> inside the vserver. If your setup does not share any resources between
> more than one vserver, it is not possible for a user (attacker or legal
> user - doesn't matter) to access filesystem resources outside the guest,
> as long as you do not give special capabilities to the guest which
> enable it to access kernel devices directly.
>
> There might be the change that the process/resource isolation code of
> vserver itself has bugs - in this case you will obvioulsy loose this
> security.
>
> | Is a vserver context more secure than a chroot jail?
>
> AFAIK a jail hides the filesystem but not processes - so I would give a
> yes at least regarding this issue.
>
> Oliver

So,
would you implement a server to give a few services (dns, webserver, dhcp, 
etc.) putting each of these services in a different vserver, just to have a 
system more secure?

What do you think about having a ssh server in each vserver and not in the 
main context? Is this setup more secure?

Thanks.