ISC DHCP: dhcpd Denial of service

Background

ISC DHCP is the reference implementation of the Dynamic Host Configuration Protocol as specified in RFC 2131.

Description

Christoph Biedl discovered that dhcpd does not properly handle certain DHCP requests when configured both using “dhcp-client-identifier” and “hardware ethernet”.

Impact

A remote attacker might send a specially crafted request to dhcpd, possibly resulting in a Denial of Service (daemon crash).

Workaround

There is no known workaround at this time.

Resolution

All ISC DHCP users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-misc/dhcp-3.1.2_p1"