libxml2 security update

CentOS Errata and Security Advisory CESA-2012:0018

The libxml2 library is a development toolbox providing the implementation
of various XML standards.

A heap-based buffer overflow flaw was found in the way libxml2 decoded
entity references with long names. A remote attacker could provide a
specially-crafted XML file that, when opened in an application linked
against libxml2, would cause the application to crash or, potentially,
execute arbitrary code with the privileges of the user running the
application. (CVE-2011-3919)

An out-of-bounds memory read flaw was found in libxml2. A remote attacker
could provide a specially-crafted XML file that, when opened in an
application linked against libxml2, would cause the application to crash.
(CVE-2011-3905)

All users of libxml2 are advised to upgrade to these updated packages,
which contain backported patches to correct these issues. The desktop must
be restarted (log out, then log back in) for this update to take effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2012-January/080536.html

Affected packages:
libxml2
libxml2-devel
libxml2-python
libxml2-static

Upstream details at:
https://access.redhat.com/errata/RHSA-2012:0018