Important: xen security and bug fix update
Security Advisory: Important
Updated xen packages that resolve a couple of security issues and fix a bug
are now available for Red Hat Enterprise Linux 5.
This update has been rated as having important security impact by the Red
Hat Security Response Team.
The xen packages contain tools for managing the virtual machine monitor in
Red Hat Virtualization.
It was discovered that the hypervisor's para-virtualized framebuffer (PVFB)
backend failed to validate the frontend's framebuffer description properly.
This could allow a privileged user in the unprivileged domain (DomU) to
cause a denial of service, or, possibly, elevate privileges to the
privileged domain (Dom0). (CVE-2008-1952)
A flaw was found in the QEMU block format auto-detection, when running
fully-virtualized guests and using Qemu images written on removable media
(USB storage, 3.5" disks). Privileged users of such fully-virtualized
guests (DomU), with a raw-formatted disk image, were able to write a header
to that disk image describing another format. This could allow such guests
to read arbitrary files in their hypervisor's host (Dom0). (CVE-2008-1945)
Additionally, the following bug is addressed in this update:
Users of xen are advised to upgrade to these updated packages, which
resolve these security issues and fix this bug.
Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.
This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/FAQ_58_10188
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