RHSA-2014:0103 - Security Advisory

Topic

Updated libvirt packages that fix two security issues and one bug are now
available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

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.

A use-after-free flaw was found in the way several libvirt block APIs
handled domain jobs. A remote attacker able to establish a read-only
connection to libvirtd could use this flaw to crash libvirtd or,
potentially, execute arbitrary code with the privileges of the libvirtd
process (usually root). (CVE-2013-6458)

A race condition was found in the way libvirtd handled keepalive
initialization requests when the connection was closed prior to
establishing connection credentials. An attacker able to establish a
read-only connection to libvirtd could use this flaw to crash libvirtd,
resulting in a denial of service. (CVE-2014-1447)

This update also fixes the following bug:

• A race condition was possible between a thread starting a virtual machine

with a guest agent configured (regular start-up or while migrating) and a
thread that was killing the VM process (or the process crashing). The race
could cause the monitor object to be freed by the thread that killed the VM
process, which was later accessed by the thread that was attempting to
start the VM, resulting in a crash. This issue was fixed by checking the
state of the VM after the attempted connection to the guest agent; if the
VM in the meantime exited, no other operations are attempted. (BZ#1055578)

All libvirt users 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.

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
https://access.redhat.com/site/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Server 6 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.5 i386
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.5 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.5 ppc64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Virtualization 3 for RHEL 6 x86_64
• Red Hat Enterprise Linux Server - AUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 i386
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server - TUS 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 6 s390x
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.5 i386
• Red Hat Enterprise Linux EUS Compute Node 6.5 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 i386
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension (for IBM z Systems) 6 s390x

Fixes

• BZ - 1048631 - CVE-2013-6458 qemu: job usage issue in several APIs leading to libvirtd crash
• BZ - 1052957 - CVE-2014-1447 libvirt: denial of service with keepalive
• BZ - 1055578 - bidirectional VMs migration between 2 hosts fail on VM doesn't exist / fatal error

CVEs

• CVE-2013-6458
• CVE-2014-1447

References

• https://access.redhat.com/security/updates/classification/#moderate