Important CentOS ntp Security Update


ntp-4.2.6p5-19.el7.centos.3.src.rpm, ntp-4.2.6p5-19.el7.centos.3.x86_64.rpm, ntp-4.2.6p5-5.el6.centos.2.i686.rpm, ntp-4.2.6p5-5.el6.centos.2.src.rpm, ntp-4.2.6p5-5.el6.centos.2.x86_64.rpm, ntp-doc-4.2.6p5-19.el7.centos.3.noarch.rpm, ntp-doc-4.2.6p5-5.el6.centos.2.noarch.rpm, ntp-perl-4.2.6p5-19.el7.centos.3.noarch.rpm, ntp-perl-4.2.6p5-5.el6.centos.2.i686.rpm, ntp-perl-4.2.6p5-5.el6.centos.2.x86_64.rpm, ntpdate-4.2.6p5-19.el7.centos.3.x86_64.rpm, ntpdate-4.2.6p5-5.el6.centos.2.i686.rpm, ntpdate-4.2.6p5-5.el6.centos.2.x86_64.rpm, sntp-4.2.6p5-19.el7.centos.3.x86_64.rpm,,
2018-01-18 11:10
2017-07-31 19:36
2017-07-27 19:10
2017-04-01 19:09
2017-01-05 20:13


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

Red Hat Product Security has rated this update as having Important security
impact. Common Vulnerability Scoring System (CVSS) base scores, which give
detailed severity ratings, are available for each vulnerability from the
CVE links 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 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)

It was found that ntpd did not correctly implement the threshold limitation
for the '-g' option, which is used to set the time without any
restrictions. A man-in-the-middle attacker able to intercept NTP traffic
between a connecting client and an NTP server could use this flaw to force
that client to make multiple steps larger than the panic threshold,
effectively changing the time to an arbitrary value. (CVE-2015-5300)

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

All ntp users are advised to upgrade to these updated packages, which
contain backported patches to resolve these issues. After installing the
update, the ntpd daemon will restart automatically.
Please see

Am I vulnerable?

The constraints below list the versions that this vulnerability is patched in, and versions that are unaffected. If a patch is ready but unrealeased, then it is pending.

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Affected package information

Release Package Patched in
6 ntp ntp-4.2.6p5-5.el6.centos.2.x86_64.rpm
ntp ntp-4.2.6p5-5.el6.centos.2.src.rpm
ntp ntp-4.2.6p5-5.el6.centos.2.i686.rpm
ntpdate ntpdate-4.2.6p5-5.el6.centos.2.x86_64.rpm
ntpdate ntpdate-4.2.6p5-5.el6.centos.2.i686.rpm
ntp-doc ntp-doc-4.2.6p5-5.el6.centos.2.noarch.rpm
ntp-perl ntp-perl-4.2.6p5-5.el6.centos.2.i686.rpm
ntp-perl ntp-perl-4.2.6p5-5.el6.centos.2.x86_64.rpm
7 ntp ntp-4.2.6p5-19.el7.centos.3.x86_64.rpm
ntp ntp-4.2.6p5-19.el7.centos.3.src.rpm
ntpdate ntpdate-4.2.6p5-19.el7.centos.3.x86_64.rpm
ntp-doc ntp-doc-4.2.6p5-19.el7.centos.3.noarch.rpm
ntp-perl ntp-perl-4.2.6p5-19.el7.centos.3.noarch.rpm
sntp sntp-4.2.6p5-19.el7.centos.3.x86_64.rpm