[USN-3843-2] pixman vulnerability

==========================================================================
Ubuntu Security Notice USN-3843-2
December 11, 2018

pixman vulnerability
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 12.04 ESM

Summary:

pixman could be made to crash or run programs if it processed specially
crafted instructions.

Software Description:
- pixman: pixel-manipulation library for X and cairo

Details:

USN-3843-1 fixed a vulnerability in pixman. This update provides
the corresponding update for Ubuntu 12.04 ESM.

Original advisory details:

 It was discovered that pixman incorrectly handled the
 general_composite_rect function. A remote attacker could use this
 issue to cause pixman to crash, resulting in a denial of service, or  
possibly execute arbitrary code.

Update instructions:

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

Ubuntu 12.04 ESM:
  libpixman-1-0                   0.30.2-1ubuntu0.0.0.0.4

After a standard system update you need to restart your session to make
all the necessary changes.

References:
  https://usn.ubuntu.com/usn/usn-3843-2
  https://usn.ubuntu.com/usn/usn-3843-1
  CVE-2015-5297