DHCP could be made to crash if it received specially crafted network traffic.
Glen Eustace discovered that the DHCP server incorrectly handled IPv6 expiration times. A remote attacker could use this issue to cause DHCP to crash, resulting in a denial of service. This issue only affected Ubuntu 11.04, Ubuntu 11.10 and Ubuntu 12.04 LTS. (CVE-2012-3955)
18 September 2012
A security issue affects these releases of Ubuntu and its derivatives:
DHCP could be made to crash if it received specially crafted network traffic.
Glen Eustace discovered that the DHCP server incorrectly handled IPv6 expiration times. A remote attacker could use this issue to cause DHCP to crash, resulting in a denial of service. This issue only affected Ubuntu 11.04, Ubuntu 11.10 and Ubuntu 12.04 LTS. (CVE-2012-3955)
Dan Rosenberg discovered that the DHCP AppArmor profile could be escaped by using environment variables. This update mitigates the issue by sanitizing certain variables in the DHCP shell scripts.
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.
Vulmon