Oracle Linux 6 : libvirt (ELSA-2013-0831)
Medium Nessus Plugin ID 68824
SynopsisThe remote Oracle Linux host is missing one or more security updates.
DescriptionFrom Red Hat Security Advisory 2013:0831 :
Updated libvirt packages that fix one security issue and two bugs are now available for Red Hat Enterprise Linux 6.
The Red Hat Security Response Team has rated this update as having moderate 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 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 remote management of virtualized systems.
It was found that libvirtd leaked file descriptors when listing all volumes for a particular pool. A remote attacker able to establish a read-only connection to libvirtd could use this flaw to cause libvirtd to consume all available file descriptors, preventing other users from using libvirtd services (such as starting a new guest) until libvirtd is restarted. (CVE-2013-1962)
Red Hat would like to thank Edoardo Comar of IBM for reporting this issue.
This update also fixes the following bugs :
* Previously, libvirt made control group (cgroup) requests on files that it should not have. With older kernels, such nonsensical cgroup requests were ignored; however, newer kernels are stricter, resulting in libvirt logging spurious warnings and failures to the libvirtd and audit logs. The audit log failures displayed by the ausearch tool were similar to the following :
root [date] - failed cgroup allow path rw /dev/kqemu
With this update, libvirt no longer attempts the nonsensical cgroup actions, leaving only valid attempts in the libvirtd and audit logs (making it easier to search for real cases of failure). (BZ#958837)
* Previously, libvirt used the wrong variable when constructing audit messages. This led to invalid audit messages, causing ausearch to format certain entries as having 'path=(null)' instead of the correct path. This could prevent ausearch from locating events related to cgroup device ACL modifications for guests managed by libvirt. With this update, the audit messages are generated correctly, preventing loss of audit coverage. (BZ#958839)
All users of libvirt are advised to upgrade to these updated packages, which contain backported patches to correct these issues. After installing the updated packages, libvirtd will be restarted automatically.
SolutionUpdate the affected libvirt packages.