chroot - how safe
Stuart Lynne
that there are some ways for people to escape out. Would enjoy hearing any
comments, horror stories etc about the use of chroot() to setup a secure
area. How secure is it? How insecure? Is it worthwhile or just a false sense
of security.
The users within the secure area would (hopefully) be allowed shell (ksh)
access, with minimal facilities like mail, news, ftp to/from their home
directories.
The specific target system is SCO UNIX (which means that Secureware might
get in the way), but presumably there are generic problems with chroot as
well.
Post or email as you think appropriate, I will not summarize email messages
unless specifically allowed by sender. Thanks in advance for any comments.
--
Stuart Lynne Computer Signal Corporation, Canada
...!van-bc!sl 604-937-7785 604-937-7718(fax) s...@wimsey.bc.ca
Mike Haertel
>I've been asked to implement a secure sub-system via chroot(). I've heard
>that there are some ways for people to escape out. Would enjoy hearing any
>comments, horror stories etc about the use of chroot() to setup a secure
>area. How secure is it? How insecure? Is it worthwhile or just a false sense
>of security.
Chroot is not secure. Anyone in the chroot'd subsystem who manages
to become root can then walk all over the system via mknod(2) and
raw device files. In fact, one could probably escape completely
by writing to /dev/kmem.