Jail security

[Frank de Bot]

Jorn Argelo wrote:
> On Mon, 07 Mar 2005 17:04:41 +0100, Frank de Bot wrote
> 
>>Hi,
>>
>>I've set up a jail. But I don't have any idea how safe a jail is. 
>>Often is told chroot and jails can be escaped. How safe is it to 
>>give other people user access to a jailed environment? or maybe even 
>>root...
> 
> 
> A jailed process cannot leave its jail. Unless some exploit is being found in
> jail itself, but that's rather unlikely. A cracker can only mess up your jail
> and not your entire host. So if you build 4 jails for Apache, MySQL, Squid and
> Postfix for instance, each of those processes will only run in its jail and
> cannot interact with another jail or the host. Which is more secure then just
> putting everything on your host.
> 
> Another major advantage of jails is that you can experiment at will without 
> touching your production enviroment. Just create a jail and install apache in
> the other jail. Once you are finished and it works, just amend your firewall
> settings and you're ready to go.
> 
> If you're experienced enough I'd encourage you to use them. It can be
> complicated for a newbie, but if you know your way around FreeBSD and the
> command line, you should really use jails.
> 
> Jorn.


What if an exploit is found, then root should have the greatest chance 
to break out of the jail, or not?
Should it be possible to assign root another UID in a jail (this is 
pretty unlikely I think), so IF it breaks out it will find hisself 
working as a user at the host system :-P