RHEL 5 : xen (RHSA-2012:1236)
High Nessus Plugin ID 61793
SynopsisThe remote Red Hat host is missing one or more security updates.
DescriptionUpdated xen packages that fix one security issue are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.
The xen packages contain administration tools and the xend service for managing the kernel-xen kernel for virtualization on Red Hat Enterprise Linux.
A flaw was found in the way QEMU handled VT100 terminal escape sequences when emulating certain character devices. A guest user with privileges to write to a character device that is emulated on the host using a virtual console back-end could use this flaw to crash the qemu process on the host or, possibly, escalate their privileges on the host. (CVE-2012-3515)
This flaw did not affect the default use of the Xen hypervisor implementation in Red Hat Enterprise Linux 5. This problem only affected fully-virtualized guests that have a serial or parallel device that uses a virtual console (vc) back-end. By default, the virtual console back-end is not used for such devices; only guests explicitly configured to use them in this way were affected.
Red Hat would like to thank the Xen project for reporting this issue.
All users of xen are advised to upgrade to these updated packages, which correct this issue. After installing the updated packages, all fully-virtualized guests must be restarted for this update to take effect.
SolutionUpdate the affected packages.