=========================================================================Ubuntu Security Notice USN-1705-1
January 28, 2013

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

- Ubuntu 12.10
- Ubuntu 12.04 LTS
- Ubuntu 11.10

Summary:

Libav could be made to crash or run programs as your login if it opened a
specially crafted file.

Software Description:
- libav: Multimedia player, server, encoder and transcoder

Details:

It was discovered that Libav incorrectly handled certain malformed media
files. If a user were tricked into opening a crafted media file, an
attacker could cause a denial of service via application crash, or possibly
execute arbitrary code with the privileges of the user invoking the
program.

Update instructions:

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

Ubuntu 12.10:
  libavcodec53                    6:0.8.5-0ubuntu0.12.10.1
  libavformat53                   6:0.8.5-0ubuntu0.12.10.1

Ubuntu 12.04 LTS:
  libavcodec53                    4:0.8.5-0ubuntu0.12.04.1
  libavformat53                   4:0.8.5-0ubuntu0.12.04.1

Ubuntu 11.10:
  libavcodec53                    4:0.7.6-0ubuntu0.11.10.3
  libavformat53                   4:0.7.6-0ubuntu0.11.10.3

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-1705-1
  CVE-2012-2783, CVE-2012-2791, CVE-2012-2797, CVE-2012-2798,
  CVE-2012-2801, CVE-2012-2802, CVE-2012-2803, CVE-2012-2804,
  CVE-2012-5144

Package Information:
  https://launchpad.net/ubuntu/+source/libav/6:0.8.5-0ubuntu0.12.10.1
  https://launchpad.net/ubuntu/+source/libav/4:0.8.5-0ubuntu0.12.04.1
  https://launchpad.net/ubuntu/+source/libav/4:0.7.6-0ubuntu0.11.10.3