The remote host is missing an update to the system as announced in the referenced advisory.

Update your system with the appropriate patches or software upgrades. https://www.isc.org/software/dhcp/advisories/cve-2011-4868 http://www.vuxml.org/freebsd/1800886c-3dde-11e1-89b4-001ec9578670.html

The following package is affected: isc-dhcp42-server CVE-2011-4868 The logging functionality in dhcpd in ISC DHCP before 4.2.3-P2, when using Dynamic DNS (DDNS) and issuing IPv6 addresses, does not properly handle the DHCPv6 lease structure, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via crafted packets related to a lease-status update.