(RHSA-2011:0479) Moderate: libvirt security and bug fix update

The libvirt library is a C API for managing and interacting with the
virtualization capabilities of Linux and other operating systems. In
addition, libvirt provides tools for remotely managing virtualized systems.

A flaw was found in the way libvirtd handled error reporting for concurrent
connections. A remote attacker able to establish read-only connections to
libvirtd on a server could use this flaw to crash libvirtd. (CVE-2011-1486)

This update also fixes the following bug:

• Previously, running qemu under a different UID prevented it from
  accessing files with mode 0660 permissions that were owned by a different
  user, but by a group that qemu was a member of. (BZ#668692)

All libvirt users are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues. After installing the
updated packages, libvirtd must be restarted (“service libvirtd restart”)
for this update to take effect.