RHSA-2016:0063 — Security Advisory

Updated ntp packages that fix one security issue are now available for Red Hat Enterprise Linux 6 and 7.

Red Hat Product Security has rated this update as having Important security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

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 the originate timestamp in received packets. A remote attacker could use this flaw to send a crafted packet to an ntpd client that would effectively disable synchronization with the server, or push arbitrary offset/delay measurements to modify the time on the client. (CVE-2015-8138)

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.