Scientific Linux Security Update : libvirt on SL7.x x86_64

This script is Copyright (C) 2015 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing one or more security
updates.

Description :

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)

This update also fixes the following bugs :

- In Scientific Linux 6, libvirt relies on the QEMU
emulator to supply the error message when an active
commit is attempted. However, with Scientific Linux 7,
QEMU added support for an active commit, but an
additional interaction from libvirt to fully enable
active commits is still missing. As a consequence,
attempts to perform an active commit caused libvirt to
become unresponsive. With this update, libvirt has been
fixed to detect an active commit by itself, and now
properly declares the feature as unsupported. As a
result, libvirt no longer hangs when an active commit is
attempted and instead produces an error message.

- Prior to this update, the libvirt API did not properly
check whether a Discretionary Access Control (DAC)
security label is non-NULL before trying to parse
user/group ownership from it. In addition, the DAC
security label of a transient domain that had just
finished migrating to another host is in some cases
NULL. As a consequence, when the virDomainGetBlockInfo
API was called on such a domain, the libvirtd daemon
sometimes terminated unexpectedly. With this update,
libvirt properly checks DAC labels before trying to
parse them, and libvirtd thus no longer crashes in the
described scenario.

- If a block copy operation was attempted while another
block copy was already in progress to an explicit raw
destination, libvirt previously stopped regarding the
destination as raw. As a consequence, if the qemu.conf
file was edited to allow file format probing, triggering
the bug could allow a malicious guest to bypass sVirt
protection by making libvirt regard the file as non-raw.
With this update, libvirt has been fixed to consistently
remember when a block copy destination is raw, and
guests can no longer circumvent sVirt protection when
the host is configured to allow format probing.

After installing the updated packages, libvirtd will be restarted
automatically.

See also :

http://www.nessus.org/u?a1008ad1

Solution :

Update the affected packages.

Risk factor :

Medium / CVSS Base Score : 5.0
(CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 80397 ()

Bugtraq ID:

CVE ID: CVE-2014-7823

Ready to Amp Up Your Nessus Experience?

Get Nessus Professional to scan unlimited IPs, run compliance checks & more

Buy Nessus Professional Now