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Fencer Intel
medium 5.3

CVE-2018-7170 json

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 arbitrari…

published 2018-03-06 8 y ago modified 2026-06-17 4 mo ago also EUVD-2018-18912

cvss
5.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.7%
EPSS 2.7% chance of exploitation in 30 days, percentile 85%
public exploits
0
none known

Summary

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.

Patch / fix

  • ntp ntp 4.2.8, 4.3.92
  • synology router_manager 1.1.6-6931-3
  • synology skynas 6.1.5-15254
  • synology virtual_diskstation_manager 6.1.6-15266
  • hpe hpux-ntp c.4.2.8.4.0
  • synology diskstation_manager 6.1.6-15266
  • synology vs960hd_firmware 2.2.3-1505
  • ntp Debian 11 1:4.2.8p11+dfsg-1

debian advisories DEBIAN-CVE-2018-7170

  • ntp SLES 12 SP3, SLES 12 SP2-BCL, SLED 12 SP3 +7 more 4.2.8p12-64.8.2
  • ntp SLE Module for Legacy 15 4.2.8p12-4.3.2
  • ntp SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLE Point of Sale 11 SP3 4.2.8p12-48.21.1
  • ntp SLES for SAP 11 SP4, SLES 11 SP4 4.2.8p12-64.7.1
  • ntp SLES 12 SP3, SLES 12 SP2-BCL, SLED 12 SP3 +7 more 4.2.8p11-64.5.1
  • ntp SLES for SAP 12 SP3, SLES 12 SP3, SLED 12 SP3 4.2.8p11-64.3.2
  • ntp SLES for SAP 11 SP4, SLES 11 SP4 4.2.8p11-64.4.1
  • ntp SLES 12-LTSS 4.2.8p12-46.29.2

suse advisories SUSE-SU-2018:3342-2SUSE-SU-2018:3386-1SUSE-SU-2018:3356-1SUSE-SU-2018:3352-1SUSE-SU-2018:3342-1SUSE-SU-2018:3351-1

  • ntp openSUSE Tumbleweed 4.2.8p15-7.2

opensuse advisories openSUSE-SU-2024:11102-1

  • ntp Arch Linux 4.2.8.p11-1

arch linux advisories AVG-647

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-7170 updated cvss 3.1

ntp: Ephemeral association time spoofing additional protection

  • Red Hat Enterprise Linux 5 ntp Red Hat Enterprise Linux 6 ntp, ntpdate, ntp-perl Red Hat Enterprise Linux 7 ntp, sntp, ntpdate, ntp-perl
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux 8 ntp
    affected: no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.69% chance of exploitation in the next 30 days, higher than 85% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 5.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:H/A:N
NVD 2.0 3.5 AV:N/AC:M/Au:S/C:N/I:P/A:N

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.