xorg security update

CentOS Errata and Security Advisory CESA-2011:1155

X.Org is an open source implementation of the X Window System. It provides
the basic low-level functionality that full-fledged graphical user
interfaces are designed upon. These xorg-x11 packages also provide the
X.Org libXfont runtime library.

A buffer overflow flaw was found in the way the libXfont library, used by
the X.Org server, handled malformed font files compressed using UNIX
compress. A malicious, local user could exploit this issue to potentially
execute arbitrary code with the privileges of the X.Org server.
(CVE-2011-2895)

Users of xorg-x11 should upgrade to these updated packages, which contain
a backported patch to resolve this issue. All running X.Org server
instances must be restarted for the update to take effect.

Merged security bulletin from advisories:
https://lists.centos.org/pipermail/centos-announce/2011-August/079823.html
https://lists.centos.org/pipermail/centos-announce/2011-August/079824.html

Affected packages:
xorg-x11
xorg-x11-Mesa-libGL
xorg-x11-Mesa-libGLU
xorg-x11-Xdmx
xorg-x11-Xnest
xorg-x11-Xvfb
xorg-x11-deprecated-libs
xorg-x11-deprecated-libs-devel
xorg-x11-devel
xorg-x11-doc
xorg-x11-font-utils
xorg-x11-libs
xorg-x11-sdk
xorg-x11-tools
xorg-x11-twm
xorg-x11-xauth
xorg-x11-xdm
xorg-x11-xfs

Upstream details at:
https://access.redhat.com/errata/RHSA-2011:1155