CentOS Errata and Security Advisory CESA-2009:0003
The xen packages contain the Xen tools and management daemons needed to manage virtual machines running on Red Hat Enterprise Linux.
Xen was found to allow unprivileged DomU domains to overwrite xenstore values which should only be changeable by the privileged Dom0 domain. An attacker controlling a DomU domain could, potentially, use this flaw to kill arbitrary processes in Dom0 or trick a Dom0 user into accessing the text console of a different domain running on the same host. This update makes certain parts of the xenstore tree read-only to the unprivileged DomU domains. (CVE-2008-4405)
It was discovered that the qemu-dm.debug script created a temporary file in /tmp in an insecure way. A local attacker in Dom0 could, potentially, use this flaw to overwrite arbitrary files via a symlink attack. Note: This script is not needed in production deployments and therefore was removed and is not shipped with updated xen packages. (CVE-2008-4993)
This update also fixes the following bug:
All xen users are advised to upgrade to these updated packages, which contain backported patches to resolve these issues. The Xen host must be restarted for the update to take effect.
Merged security bulletin from advisories: http://lists.centos.org/pipermail/centos-announce/2009-January/015534.html http://lists.centos.org/pipermail/centos-announce/2009-January/015535.html
Affected packages: xen xen-devel xen-libs
Upstream details at: https://rhn.redhat.com/errata/RHSA-2009-0003.html