Ubuntu Security Notice USN-1108-2

Ubuntu Security Notice 1108-2 – USN-1108-1 fixed vulnerabilities in DHCP. Due to an error, the patch to fix the vulnerability was not properly applied on Ubuntu 9.10 and higher. This update fixes the problem. Sebastian Krahmer discovered that the dhclient utility incorrectly filtered crafted responses. An attacker could use this flaw with a malicious DHCP server to execute arbitrary code, resulting in root privilege escalation.

Source: Ubuntu Security Notice USN-1108-2