isc-dhcp -- multiple vulnerabilities

ISC reports:

An unexpected client identifier parameter can cause the ISC DHCP
daemon to segmentation fault when running in DHCPv6 mode,
resulting in a denial of service to further client requests. In
order to exploit this condition, an attacker must be able to send
requests to the DHCP server.
An error in the handling of malformed client identifiers can cause
a DHCP server running affected versions (see “Impact”) to enter a
state where further client requests are not processed and the
server process loops endlessly, consuming all available CPU
cycles.
Under normal circumstances this condition should not be
triggered, but a non-conforming or malicious client could
deliberately trigger it in a vulnerable server. In order to
exploit this condition an attacker must be able to send requests
to the DHCP server.
Two memory leaks have been found and fixed in ISC DHCP. Both are
reproducible when running in DHCPv6 mode (with the -6 command-line
argument.) The first leak is confirmed to only affect servers
operating in DHCPv6 mode, but based on initial code analysis the
second may theoretically affect DHCPv4 servers (though this has
not been demonstrated.)