Issued:
2011-12-06
Updated:
2011-12-06

RHSA-2011:1531 - Moderate: qemu-kvm security, bug fix, and enhancement update

Synopsis

Moderate: qemu-kvm security, bug fix, and enhancement update

Type/Severity

Security Advisory Moderate

Topic

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.

Description

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.

Solution

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at This content is not included.https://access.redhat.com/kb/docs/DOC-11259

Affected Products

ProductVersionArch
Red Hat Enterprise Linux for Scientific Computing6x86_64
Red Hat Enterprise Linux Workstation6x86_64
Red Hat Enterprise Linux Server6x86_64
Red Hat Enterprise Linux Server from RHUI6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support6x86_64
Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension6x86_64
Red Hat Enterprise Linux Desktop6x86_64

Updated Packages

  • qemu-img-0.12.1.2-2.209.el6.x86_64.rpm
  • qemu-kvm-tools-0.12.1.2-2.209.el6.x86_64.rpm
  • qemu-kvm-0.12.1.2-2.209.el6.src.rpm
  • qemu-kvm-0.12.1.2-2.209.el6.x86_64.rpm
  • qemu-kvm-debuginfo-0.12.1.2-2.209.el6.x86_64.rpm

Fixes

CVEs

References

Additional information