(RHSA-2013:1620) Low: xorg-x11-server security and bug fix update

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.

A flaw was found in the way the X.org X11 server registered new hot plugged
devices. If a local user switched to a different session and plugged in a
new device, input from that device could become available in the previous
session, possibly leading to information disclosure. (CVE-2013-1940)

This issue was found by David Airlie and Peter Hutterer of Red Hat.

This update also fixes the following bugs:

• A previous upstream patch modified the Xephyr X server to be resizeable,
  however, it did not enable the resize functionality by default. As a
  consequence, X sandboxes were not resizeable on Red Hat Enterprise Linux
  6.4 and later. This update enables the resize functionality by default so
  that X sandboxes can now be resized as expected. (BZ#915202)

• In Red Hat Enterprise Linux 6, the X Security extension (XC-SECURITY)
  has been disabled and replaced by X Access Control Extension (XACE).
  However, XACE does not yet include functionality that was previously
  available in XC-SECURITY. With this update, XC-SECURITY is enabled in the
  xorg-x11-server spec file on Red Hat Enterprise Linux 6. (BZ#957298)

• Upstream code changes to extension initialization accidentally disabled
  the GLX extension in Xvfb (the X virtual frame buffer), rendering headless
  3D applications not functional. An upstream patch to this problem has been
  backported so the GLX extension is enabled again, and applications relying
  on this extension work as expected. (BZ#969538)

All xorg-x11-server users are advised to upgrade to these updated packages,
which contain backported patches to correct these issues.