(RHSA-2012:1141) Moderate: dhcp security update

The Dynamic Host Configuration Protocol (DHCP) is a protocol that allows
individual devices on an IP network to get their own network configuration
information, including an IP address, a subnet mask, and a broadcast
address.

A denial of service flaw was found in the way the dhcpd daemon handled
zero-length client identifiers. A remote attacker could use this flaw to
send a specially-crafted request to dhcpd, possibly causing it to enter an
infinite loop and consume an excessive amount of CPU time. (CVE-2012-3571)

Two memory leak flaws were found in the dhcpd daemon. A remote attacker
could use these flaws to cause dhcpd to exhaust all available memory by
sending a large number of DHCP requests. (CVE-2012-3954)

Upstream acknowledges Markus Hietava of the Codenomicon CROSS project as
the original reporter of CVE-2012-3571, and Glen Eustace of Massey
University, New Zealand, as the original reporter of CVE-2012-3954.

Users of DHCP should upgrade to these updated packages, which contain
backported patches to correct these issues. After installing this update,
all DHCP servers will be restarted automatically.