The remote NTP server responds to mode 6 queries. Devices that respond to these queries have the potential to be used in NTP amplification attacks. An unauthenticated, remote attacker could potentially exploit this, via a specially crafted mode 6 query, to cause a reflected denial of service condition.
Restrict NTP mode 6 queries.
See Also
  •   Nessus elicited the following response from the remote
      host by sending an NTP mode 6 query :
    'version="ntpd 4.2.0-a Tue Sep 11 05:30:54  2018 (1)",
    processor="powerpc", system="JUNOS15.1R7.9", leap=0, stratum=5,
    precision=-18, rootdelay=158.158, rootdispersion=201.049, peer=15396,
    refid=, reftime=0xe07f4739.426e96ba, poll=10,
    clock=0xe07f4ad5.c89721cd, state=4, offset=-2.686, frequency=-37.253,
    jitter=13.382, stability=0.321'