CVE-2018-7170

Name: CVE-2018-7170
Creator: NVD / NIST
Published: 2018-03-06T20:29:01.297+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10EPSS 2.76%

Last modified Jun 17, 2026

CVE-2018-7170 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.. EPSS estimates a 2.76% chance of exploitation in the next 30 days.

Description

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549.

Metrics

CVSS 3.1

5.3/10

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N

EPSS Probability

2.76%

84.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions
Ntp	Ntp	>= 4.2.0, < 4.2.8
Ntp	Ntp	>= 4.3.0, < 4.3.92
Ntp	Ntp	4.2.8
Synology	Router Manager	>= 1.1, < 1.1.6-6931-3
Synology	Skynas	< 6.1.5-15254
Synology	Virtual Diskstation Manager	< 6.1.6-15266
Synology	Diskstation Manager	>= 5.2, < 6.1.6-15266
Synology	Vs960hd Firmware	< 2.2.3-1505
Netapp	Hci	All versions
Netapp	Solidfire	All versions
Hpe	Hpux-Ntp	< c.4.2.8.4.0

References

http://packetstormsecurity.com/files/146631/Slackware-Security-Advisory-ntp-Updates.htmlThird Party Advisory, VDB Entry
http://support.ntp.org/bin/view/Main/NtpBug3415Third Party Advisory
http://www.securityfocus.com/archive/1/541824/100/0/threadedThird Party Advisory, VDB Entry
http://www.securityfocus.com/bid/103194Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1550214Issue Tracking, Third Party Advisory
https://security.FreeBSD.org/advisories/FreeBSD-SA-18:02.ntp.ascThird Party Advisory
https://security.gentoo.org/glsa/201805-12Third Party Advisory
https://security.netapp.com/advisory/ntap-20180626-0001/Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_usThird Party Advisory
https://www.synology.com/support/security/Synology_SA_18_13Third Party Advisory
http://packetstormsecurity.com/files/146631/Slackware-Security-Advisory-ntp-Updates.htmlThird Party Advisory, VDB Entry
http://support.ntp.org/bin/view/Main/NtpBug3415Third Party Advisory
http://www.securityfocus.com/archive/1/541824/100/0/threadedThird Party Advisory, VDB Entry
http://www.securityfocus.com/bid/103194Third Party Advisory, VDB Entry
https://bugzilla.redhat.com/show_bug.cgi?id=1550214Issue Tracking, Third Party Advisory
https://security.FreeBSD.org/advisories/FreeBSD-SA-18:02.ntp.ascThird Party Advisory
https://security.gentoo.org/glsa/201805-12Third Party Advisory
https://security.netapp.com/advisory/ntap-20180626-0001/Third Party Advisory
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_usThird Party Advisory
https://www.synology.com/support/security/Synology_SA_18_13Third Party Advisory

Timeline

Published: Mar 6, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-7170?

How severe is CVE-2018-7170?

CVE-2018-7170 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 2.76% probability of exploitation in the next 30 days.

How do I fix CVE-2018-7170?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-7170?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST