(RHSA-2015:2520) Important: ntp security update

The Network Time Protocol (NTP) is used to synchronize a computer’s time
with a referenced time source.

It was discovered that ntpd as a client did not correctly check timestamps
in Kiss-of-Death packets. A remote attacker could use this flaw to send a
crafted Kiss-of-Death packet to an ntpd client that would increase the
client’s polling interval value, and effectively disable synchronization
with the server. (CVE-2015-7704)

Red Hat would like to thank Aanchal Malhotra, Isaac E. Cohen, and Sharon
Goldberg of Boston University for reporting this issue.

All ntp users are advised to upgrade to these updated packages, which
contain a backported patch to resolve this issue. After installing the
update, the ntpd daemon will restart automatically.