Fixes:
* CVE-2019-6472 affects the Kea DHCPv6 server, which can exit
with an assertion failure if the DHCPv6 server process receives
a request containing DUID value which is too large.
(https://kb.isc.org/docs/cve-2019-6474)
* CVE-2019-6473 affects the Kea DHCPv4 server, which can exit with
an assertion failure if it receives a packed containing a malformed
option. (https://kb.isc.org/docs/cve-2019-6473)
* CVE-2019-6474 can cause a condition where the server cannot be
restarted without manual operator intervention to correct a problem
that can be deliberately introduced into the stored leases.
CVE-2019-6474 can only affect servers which are using memfile
for lease storage. (https://kb.isc.org/docs/cve-2019-6474)
Annoucement: https://www.openwall.com/lists/oss-security/2019/08/29/1
e6e3270bd4