The system could be made to crash under certain conditions.

==========================================================================
Ubuntu Security Notice USN-1557-1
September 07, 2012

linux vulnerability
==========================================================================

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

- Ubuntu 11.04

Summary:

The system could be made to crash under certain conditions.

Software Description:
- linux: Linux kernel

Details:

Some errors where discovered in the Linux kernel's UDF file system, which
is used to mount some CD-ROMs and DVDs. An unprivileged local user could
use these flaws to crash the system.

Update instructions:

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

Ubuntu 11.04:
  linux-image-2.6.38-15-generic   2.6.38-15.66
  linux-image-2.6.38-15-generic-pae  2.6.38-15.66
  linux-image-2.6.38-15-omap      2.6.38-15.66
  linux-image-2.6.38-15-powerpc   2.6.38-15.66
  linux-image-2.6.38-15-powerpc-smp  2.6.38-15.66
  linux-image-2.6.38-15-powerpc64-smp  2.6.38-15.66
  linux-image-2.6.38-15-server    2.6.38-15.66
  linux-image-2.6.38-15-versatile  2.6.38-15.66
  linux-image-2.6.38-15-virtual   2.6.38-15.66

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

References:
  http://www.ubuntu.com/usn/usn-1557-1
  CVE-2012-3400

Package Information:
  https://launchpad.net/ubuntu/+source/linux/2.6.38-15.66