RHEL 6 : qemu-kvm (RHSA-2011:1531)

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Synopsis :

The remote Red Hat host is missing one or more security updates.

Description :

Updated qemu-kvm packages that fix one security issue, multiple bugs,
and add various enhancements 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.

KVM (Kernel-based Virtual Machine) is a full virtualization solution
for Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space
component for running virtual machines using KVM.

It was found that qemu-kvm did not properly drop supplemental group
privileges when the root user started guests from the command line
('/usr/libexec/qemu-kvm') with the '-runas' option. A qemu-kvm process
started this way could use this flaw to gain access to files on the
host that are accessible to the supplementary groups and not
accessible to the primary group. (CVE-2011-2527)

Note: This issue only affected qemu-kvm when it was started directly
from the command line. It did not affect the Red Hat Enterprise
Virtualization platform or applications that start qemu-kvm via
libvirt, such as the Virtual Machine Manager (virt-manager).

This update also fixes several bugs and adds various enhancements.
Documentation for these bug fixes and enhancements will be available
shortly from the Technical Notes document, linked to in the References
section.

All users of qemu-kvm are advised to upgrade to these updated
packages, which contain backported patches to correct these issues and
add these enhancements. After installing this update, shut down all
running virtual machines. Once all virtual machines have shut down,
start them again for this update to take effect.

See also :

https://www.redhat.com/security/data/cve/CVE-2011-2527.html
https://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html/
http://rhn.redhat.com/errata/RHSA-2011-1531.html

Solution :

Update the affected packages.

Risk factor :

Low / CVSS Base Score : 2.1
(CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N)
CVSS Temporal Score : 1.7
(CVSS2#E:F/RL:OF/RC:C)
Public Exploit Available : true

Family: Red Hat Local Security Checks

Nessus Plugin ID: 64006 ()

Bugtraq ID: 48659

CVE ID: CVE-2011-2527