RHSA-2014:1873 - Security Advisory

Topic

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

Red Hat Product Security 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.

An out-of-bounds read flaw was found in the way libvirt's
qemuDomainGetBlockIoTune() function looked up the disk index in a
non-persistent (live) disk configuration while a persistent disk
configuration was being indexed. A remote attacker able to establish a
read-only connection to libvirtd could use this flaw to crash libvirtd or,
potentially, leak memory from the libvirtd process. (CVE-2014-3633)

A denial of service flaw was found in the way libvirt's
virConnectListAllDomains() function computed the number of used domains.
A remote attacker able to establish a read-only connection to libvirtd
could use this flaw to make any domain operations within libvirt
unresponsive. (CVE-2014-3657)

It was found that when the VIR_DOMAIN_XML_MIGRATABLE flag was used, the
QEMU driver implementation of the virDomainGetXMLDesc() function could
bypass the restrictions of the VIR_DOMAIN_XML_SECURE flag. A remote
attacker able to establish a read-only connection to libvirtd could use
this flaw to leak certain limited information from the domain XML data.
(CVE-2014-7823)

The CVE-2014-3633 issue was discovered by Luyao Huang of Red Hat.

This update also fixes the following bug:

When dumping migratable XML configuration of a domain, libvirt removes some
automatically added devices for compatibility with older libvirt releases.
If such XML is passed to libvirt as a domain XML that should be used during
migration, libvirt checks this XML for compatibility with the internally
stored configuration of the domain. However, prior to this update, these
checks failed because of devices that were missing (the same devices
libvirt removed). As a consequence, migration with user-supplied migratable
XML failed. Since this feature is used by OpenStack, migrating QEMU/KVM
domains with OpenStack always failed. With this update, before checking
domain configurations for compatibility, libvirt transforms both
user-supplied and internal configuration into a migratable form
(automatically added devices are removed) and checks those instead. Thus,
no matter whether the user-supplied configuration was generated as
migratable or not, libvirt does not err about missing devices, and
migration succeeds as expected. (BZ#1155564)

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/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 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 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 x86_64
• Red Hat Enterprise Linux Workstation 6 i386
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux Desktop 6 i386
• Red Hat Enterprise Linux for IBM z Systems 6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian 6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 ppc64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 i386
• Red Hat Virtualization 3.5 x86_64
• Red Hat Virtualization 3.4 x86_64
• Red Hat Virtualization 3 for RHEL 6 x86_64
• Red Hat Gluster Storage Server for On-premise 3 for RHEL 6 x86_64
• Red Hat Enterprise Linux Server - TUS 6.6 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 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux EUS Compute Node 6.6 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 - 1141131 - CVE-2014-3633 libvirt: qemu: out-of-bounds read access in qemuDomainGetBlockIoTune() due to invalid index
• BZ - 1145667 - CVE-2014-3657 libvirt: domain_conf: domain deadlock DoS
• BZ - 1160817 - CVE-2014-7823 libvirt: dumpxml: information leak with migratable flag

CVEs

• CVE-2014-3633
• CVE-2014-3657
• CVE-2014-7823

References

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