USN-1309-1: DHCP vulnerability

Ubuntu Security Notice USN-1309-1

15th December, 2011

isc-dhcp vulnerability

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

  • Ubuntu 11.10
  • Ubuntu 11.04


DHCP could be made to crash if it received specially crafted network traffic.

Software description

  • isc-dhcp - DHCP server and client


It was discovered that the DHCP server incorrectly handled certain
malformed packets when configured to evaluate regular expressions. A remote
attacker could use this issue to cause DHCP to crash, resulting in a denial
of service.

Update instructions

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

Ubuntu 11.10:
isc-dhcp-server 4.1.1-P1-17ubuntu10.1
Ubuntu 11.04:
isc-dhcp-server 4.1.1-P1-15ubuntu9.3

To update your system, please follow these instructions:

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