Ubuntu: 1990-1: X.Org X server vulnerabilities
Posted by Benjamin D. Thomas   
Ubuntu The X.Org X server could be made to crash or run programs as anadministrator if it received specially crafted input.
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Ubuntu Security Notice USN-1990-1
October 17, 2013

xorg-server, xorg-server-lts-quantal, xorg-server-lts-raring vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 13.04
- Ubuntu 12.10
- Ubuntu 12.04 LTS

Summary:

The X.Org X server could be made to crash or run programs as an
administrator if it received specially crafted input.

Software Description:
- xorg-server: X.Org X11 server
- xorg-server-lts-quantal: X.Org X11 server
- xorg-server-lts-raring: X.Org X11 server

Details:

Pedro Ribeiro discovered that the X.Org X server incorrectly handled
memory operations when handling ImageText requests. An attacker could use
this issue to cause X.Org to crash, or to possibly execute arbitrary code.
(CVE-2013-4396)

It was discovered that non-root X.Org X servers such as Xephyr incorrectly
used cached xkb files. A local attacker could use this flaw to cause a xkb
cache file to be loaded by another user, resulting in a denial of service.
(CVE-2013-1056)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 13.04:
  xserver-xorg-core               2:1.13.3-0ubuntu6.2

Ubuntu 12.10:
  xserver-xorg-core               2:1.13.0-0ubuntu6.4

Ubuntu 12.04 LTS:
  xserver-xorg-core               2:1.11.4-0ubuntu10.14
  xserver-xorg-core-lts-quantal   2:1.13.0-0ubuntu6.1~precise4
  xserver-xorg-core-lts-raring    2:1.13.3-0ubuntu6~precise3

After a standard system update you need to reboot your computer to make
all the necessary changes.

References:
  http://www.ubuntu.com/usn/usn-1990-1
  CVE-2013-1056, CVE-2013-4396

Package Information:
  https://launchpad.net/ubuntu/+source/xorg-server/2:1.13.3-0ubuntu6.2
  https://launchpad.net/ubuntu/+source/xorg-server/2:1.13.0-0ubuntu6.4
  https://launchpad.net/ubuntu/+source/xorg-server/2:1.11.4-0ubuntu10.14

https://launchpad.net/ubuntu/+source/xorg-server-lts-quantal/2:1.13.0-0ubuntu6.1~precise4

https://launchpad.net/ubuntu/+source/xorg-server-lts-raring/2:1.13.3-0ubuntu6~precise3