RHEL 6 : libvirt (RHSA-2014:1873)

This script is Copyright (C) 2014-2017 Tenable Network Security, Inc.


Synopsis :

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

Description :

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.

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.

See also :

https://www.redhat.com/security/data/cve/CVE-2014-3633.html
https://www.redhat.com/security/data/cve/CVE-2014-3657.html
https://www.redhat.com/security/data/cve/CVE-2014-7823.html
http://rhn.redhat.com/errata/RHSA-2014-1873.html

Solution :

Update the affected packages.

Risk factor :

Medium / CVSS Base Score : 5.8
(CVSS2#AV:N/AC:M/Au:N/C:P/I:N/A:P)
CVSS Temporal Score : 5.0
(CVSS2#E:ND/RL:OF/RC:C)
Public Exploit Available : false

Family: Red Hat Local Security Checks

Nessus Plugin ID: 79329 ()

Bugtraq ID: 70186
70210
71095

CVE ID: CVE-2014-3633
CVE-2014-3657
CVE-2014-7823

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