What’s Vulnerable › Vulnerabilities

CVE-2018-7170

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.7% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2018-03-06 · updated 2026-06-17

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.

Affected products

• HPE Hpux-Ntp: before c.4.2.8.4.0 — fixed in c.4.2.8.4.0
• NetApp Hci: all versions
• NetApp Solidfire: all versions
• NTP: from 4.2.0 before 4.2.8; from 4.3.0 before 4.3.92; 4.2.8, 4.2.8-p1, 4.2.8-p1-beta1, 4.2.8-p1-beta2, 4.2.8-p1-beta3, 4.2.8-p1-beta4 (+14) — fixed in 4.2.8, 4.3.92
• Synology DiskStation Manager: from 5.2 before 6.1.6-15266 — fixed in 6.1.6-15266
• Synology Router Manager (SRM): from 1.1 before 1.1.6-6931-3 — fixed in 1.1.6-6931-3
• Synology Skynas: before 6.1.5-15254 — fixed in 6.1.5-15254
• Synology Virtual Diskstation Manager: before 6.1.6-15266 — fixed in 6.1.6-15266
• Synology Vs960Hd Firmware: before 2.2.3-1505 — fixed in 2.2.3-1505

How to fix

Upgrade to a fixed version: HPE Hpux-Ntp c.4.2.8.4.0; NTP 4.2.8, 4.3.92; Synology DiskStation Manager 6.1.6-15266; Synology Router Manager (SRM) 1.1.6-6931-3; Synology Skynas 6.1.5-15254; Synology Virtual Diskstation Manager 6.1.6-15266; Synology Vs960Hd Firmware 2.2.3-1505. Check the vendor advisory for mitigations.

References

• http://packetstormsecurity.com/files/146631/Slackware-Security-Advisory-ntp-Updates.html
• http://support.ntp.org/bin/view/Main/NtpBug3415
• http://www.securityfocus.com/archive/1/541824/100/0/threaded
• http://www.securityfocus.com/bid/103194
• https://bugzilla.redhat.com/show_bug.cgi?id=1550214
• https://security.FreeBSD.org/advisories/FreeBSD-SA-18:02.ntp.asc
• https://security.gentoo.org/glsa/201805-12
• https://security.netapp.com/advisory/ntap-20180626-0001/
• https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbux03962en_us
• https://www.synology.com/support/security/Synology_SA_18_13
• http://packetstormsecurity.com/files/146631/Slackware-Security-Advisory-ntp-Updates.html
• http://support.ntp.org/bin/view/Main/NtpBug3415

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