2010-06-01

SOA-style security for linux

news.addn/security/soa for linux:

5.6:
OpenVZ is container-based virtualization for Linux
. this is what could make linux
more secure than mac ? 5.13:
another layer of security wouldn't hurt,
but openVZ is just the open engine for
for a closed product from Parallels .
. Qubes has a complete open betaware isolation solution .

5.13: web:
Qubes is an open source operating system
designed to provide strong security for desktop computing.
Qubes is based on Xen, X Window System, and Linux,
and can run most Linux applications
and utilize most of the Linux drivers.
qubes-os.org/trac/wiki/SourceCode
qubes-os.org/gitweb/
qubes-os.org/trac/wiki/InstallationGuide
In the future it might also run Windows apps.
. critique at threatpost.com .

5.13:
Secure Virtualization Using SELinux (sVirt):
"(Crackers have already broken though the xen hypervisor,
as I documented in one of my previous blogs.

Adventures with a certain Xen vulnerability (pdf)
was just published which contains a Xen vulnerability
which allows a process in a virtual machine
to attack the host machine,
and SELinux is pretty much a speed bump in his way.
3.4
What actions are available for an uid 0 process
running in thesystem u:system r:xend t:s0 context?
It turns out that default SELinux policy allows very few.
For instance, we cannot write to system configuration files,
nor load kernel modules.
However, qemu-dm processes also implement
virtual block devices for HVM guests,
and these devices can be backed by raw disk partitions.
In order to make it possible,
the default SELinux policy grants xend t domain
the read-write access to all disk partitions.
The relevant lines in the SELinux reference policy
(from the default selinux-policy-3.0.8-44.fc8.src.rpm)
are: storage_raw_read_fixed_disk(xend_t)
storage_raw_write_fixed_disk(xend_t)
Particularly, qemu-dm (so, the shell executed from it as well)
can write to the blocks on the root filesystem.
Through the use of fixed disk the attacker
is able to trick the host operating system
into loading kernel modules that can take over the machine.
If we had forced the users to label the physical disk partitions,
this vulnerability would not have been exploitable.
Lesson learned.
When it comes to virtualization going forward,
I plan on forcing the user to apply the correct labeling.
KVM/QEMU have nice process separation
and make confinement easier.
virt_manager and libvirt are being built with SELinux
understanding in them.
virt_manager will setup the labeling correctly
when virtual images are installed
and libvirt will make sure they run in the correct domain
when they are launched.
In the future we want to protect not only the host machine
from the virtual machines,
but the virtual machines from each other.
Watch for information on in the future

In conclusion,
as we move towards more widespread use of virtualization,
we should avoid making compromises in security
for the sake of usability,
but work toward making security usable.) .
Want to know how to make Linux really secure?
http://www.linuxsecurity.com/content/blogcategory/171/167/
Security Enhanced Linux (SE Linux),
a system of security policies developed by the NSA,
lets you secure Linux at every level from the kernel up.
Find out how EnGarde Secure Linux and others
build and maintain a truly secure server environment.

secure virtualization with MAC
selinuxproject.org/page/SVirt