FreeBSD Security Advisory (FreeBSD-SA-10:02.ntpd.asc)

The remote host is missing an update to the system as announced in the referenced advisory FreeBSD-SA-10:02.ntpd.asc
Upgrade your system to the appropriate stable release or security branch dated after the correction date
The ntpd(8) daemon is an implementation of the Network Time Protocol (NTP) used to synchronize the time of a computer system to a reference time source. If ntpd receives a mode 7 (MODE_PRIVATE) request or error response from a source address not listed in either a 'restrict ... noquery' or a 'restrict ... ignore' section it will log the even and send a mode 7 error response.