RHEL 5 : xen (RHSA-2008:0892)
Medium Nessus Plugin ID 34329
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated 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 :
* The qcow-create command terminated when invoked due to glibc bounds checking on the realpath() function.
Users of xen are advised to upgrade to these updated packages, which resolve these security issues and fix this bug.
SolutionUpdate the affected xen, xen-devel and / or xen-libs packages.