Rooting FreeBSD , Privilege Escalation using Jails (P�tur)

[Jamie Landeg Jones]

> All the same, I've sent a PR [1] with some doc patches to make people
> more aware of this -- fulfilling my promise of 2+ years ago :S
>
> Thanks!
>
> Chris
>
> [1] http://www.freebsd.org/cgi/query-pr.cgi?pr=156853

Um. Some problems here.

A jail won't work for not-root users if the jail root directory is chmod 700 - although
there is obviously a 'chroot' running withing the jail, the jailed user still needs
to have read permission from the hosts / -- chmod 700 therefore locks all non-root
users out.

I would suggest you add to the docs about the UID clash problem - untrusted users on the host
shouldn't have the same UID/GID as jailed users, as they will have access to their files.

And of course, the bit mentioned earlier where an untrusted jail user with jail-root access
should NEVER have access to the host!o

Among other things, my password file in both jails and the host has this line:

# 8000 to 9999  -  Reserved for use within jails - do not use in main host!

cheers,
Jamie