ISC DHCP is the reference implementation of the Dynamic Host Configuration Protocol as specified in RFC 2131.
The Mandriva Linux Engineering Team has reported a stack-based buffer overflow in the subnet-mask handling of dhclient.
A remote attacker might set up a rogue DHCP server in a victim's local network, possibly leading to the execution of arbitrary code with root privileges.
There is no known workaround at this time.
All ISC DHCP users should upgrade to the latest version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=net-misc/dhcp-3.1.1-r1"