USN-1190-1: DHCP vulnerabilities

15 August 2011

dhcp3, isc-dhcp vulnerabilities

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

  • Ubuntu 11.04
  • Ubuntu 10.10
  • Ubuntu 10.04 LTS
  • Ubuntu 8.04 LTS


An attacker could send crafted input to DHCP and cause it to crash.

Software Description

  • isc-dhcp - DHCP server and client
  • dhcp3 - DHCP server and client


David Zych discovered that DHCP incorrectly handled certain malformed packets. 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 versions:

Ubuntu 11.04
isc-dhcp-server - 4.1.1-P1-15ubuntu9.1
Ubuntu 10.10
dhcp3-server - 3.1.3-2ubuntu6.3
Ubuntu 10.04 LTS
dhcp3-server - 3.1.3-2ubuntu3.3
Ubuntu 8.04 LTS
dhcp3-server - 3.0.6.dfsg-1ubuntu9.3

To update your system, please follow these instructions:

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