=========================================================================Ubuntu Security Notice USN-2868-1
January 13, 2016

isc-dhcp vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 15.10
- Ubuntu 15.04
- Ubuntu 14.04 LTS
- Ubuntu 12.04 LTS

Summary:

DHCP server, client, or relay could be made to crash if they received
specially crafted network traffic.

Software Description:
- isc-dhcp: DHCP server and client

Details:

Sebastian Poehn discovered that the DHCP server, client, and relay
incorrectly handled certain malformed UDP packets. A remote attacker could
use this issue to cause the DHCP server, client, or relay to stop
responding, resulting in a denial of service.

Update instructions:

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

Ubuntu 15.10:
  isc-dhcp-client                 4.3.1-5ubuntu3.1
  isc-dhcp-relay                  4.3.1-5ubuntu3.1
  isc-dhcp-server                 4.3.1-5ubuntu3.1
  isc-dhcp-server-ldap            4.3.1-5ubuntu3.1

Ubuntu 15.04:
  isc-dhcp-client                 4.3.1-5ubuntu2.3
  isc-dhcp-relay                  4.3.1-5ubuntu2.3
  isc-dhcp-server                 4.3.1-5ubuntu2.3
  isc-dhcp-server-ldap            4.3.1-5ubuntu2.3

Ubuntu 14.04 LTS:
  isc-dhcp-client                 4.2.4-7ubuntu12.4
  isc-dhcp-relay                  4.2.4-7ubuntu12.4
  isc-dhcp-server                 4.2.4-7ubuntu12.4
  isc-dhcp-server-ldap            4.2.4-7ubuntu12.4

Ubuntu 12.04 LTS:
  isc-dhcp-client                 4.1.ESV-R4-0ubuntu5.10
  isc-dhcp-relay                  4.1.ESV-R4-0ubuntu5.10
  isc-dhcp-server                 4.1.ESV-R4-0ubuntu5.10
  isc-dhcp-server-ldap            4.1.ESV-R4-0ubuntu5.10

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

References:
  https://ubuntu.com/security/notices/USN-2868-1
  CVE-2015-8605

Package Information:
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.3.1-5ubuntu3.1
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.3.1-5ubuntu2.3
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.2.4-7ubuntu12.4
  https://launchpad.net/ubuntu/+source/isc-dhcp/4.1.ESV-R4-0ubuntu5.10