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Fencer Intel
medium 6.5

CVE-2017-6463 json

NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows remote authenticated users to cause a denial of service (daemon crash) via an invalid se…

published 2017-03-27 9 y ago modified 2026-06-17 4 mo ago also EUVD-2017-15520

cvss
6.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.2%
EPSS 5.2% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

NTP before 4.2.8p10 and 4.3.x before 4.3.94 allows remote authenticated users to cause a denial of service (daemon crash) via an invalid setting in a :config directive, related to the unpeer option.

Patch / fix

  • ntp Debian 11 1:4.2.8p10+dfsg-1

debian advisories DEBIAN-CVE-2017-6463

  • ntp Ubuntu 14.04 LTS 1:4.2.6.p5+dfsg-3ubuntu2.14.04.11
  • ntp Ubuntu 16.04 LTS 1:4.2.8p4+dfsg-3ubuntu5.5

ubuntu advisories UBUNTU-CVE-2017-6463

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ntp RHEL 7 4.2.6p5-28.el7
  • sntp RHEL 7 4.2.6p5-28.el7
  • ntpdate RHEL 7 4.2.6p5-28.el7
  • ntp-perl RHEL 7 4.2.6p5-28.el7
  • ntp RHEL 6 4.2.6p5-12.el6_9.1
  • ntpdate RHEL 6 4.2.6p5-12.el6_9.1
  • ntp-perl RHEL 6 4.2.6p5-12.el6_9.1

red hat advisories RHSA-2018:0855RHSA-2017:3071

  • ntp SLES for SAP 11 SP4, SLES 11 SP4 4.2.8p10-63.1
  • ntp SLES for SAP 12 SP2, SLES for SAP 12 SP1, SLES for Raspberry Pi 12 SP2 +4 more 4.2.8p10-60.1
  • ntp SLES for SAP 12, SLES 12-LTSS 4.2.8p10-46.23.1

suse advisories SUSE-SU-2017:1052-1SUSE-SU-2017:1047-1SUSE-SU-2017:1048-1

  • ntp openSUSE Tumbleweed 4.2.8p15-7.2

opensuse advisories openSUSE-SU-2024:11102-1

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-2017-6463 updated cvss 6.5

ntp: Authenticated DoS via Malicious Config Option

  • Red Hat Enterprise Linux 5 ntp
    affected: workaround, no fix planned “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.”
  • Red Hat Enterprise Linux Client (v. 7) ntp 4.2.6p5-28.el7, ntpdate 4.2.6p5-28.el7 Red Hat Enterprise Linux Client Optional (v. 7) sntp 4.2.6p5-28.el7, ntp-perl 4.2.6p5-28.el7 Red Hat Enterprise Linux ComputeNode (v. 7) ntp 4.2.6p5-28.el7, ntpdate 4.2.6p5-28.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) sntp 4.2.6p5-28.el7, ntp-perl 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855
  • Red Hat Enterprise Linux Desktop (v. 6) ntp 4.2.6p5-12.el6_9.1, ntpdate 4.2.6p5-12.el6_9.1 Red Hat Enterprise Linux Desktop Optional (v. 6) ntp-perl 4.2.6p5-12.el6_9.1
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2017:3071
  • Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server (v. 7) ntp 4.2.6p5-28.el7, ntpdate 4.2.6p5-28.el7 Red Hat Enterprise Linux for ARM and IBM Power LE (POWER9) Server Optional (v. 7) sntp 4.2.6p5-28.el7, ntp-perl 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855
  • Red Hat Enterprise Linux HPC Node (v. 6) ntp 4.2.6p5-12.el6_9.1, ntpdate 4.2.6p5-12.el6_9.1 Red Hat Enterprise Linux HPC Node Optional (v. 6) ntp-perl 4.2.6p5-12.el6_9.1 Red Hat Enterprise Linux Server (v. 6) ntp 4.2.6p5-12.el6_9.1, ntpdate 4.2.6p5-12.el6_9.1
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2017:3071
  • Red Hat Enterprise Linux Server (v. 7) ntp 4.2.6p5-28.el7, ntpdate 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855
  • Red Hat Enterprise Linux Server Optional (v. 6) ntp-perl 4.2.6p5-12.el6_9.1
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2017:3071
  • Red Hat Enterprise Linux Server Optional (v. 7) sntp 4.2.6p5-28.el7, ntp-perl 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855
show 4 more
  • Red Hat Enterprise Linux Workstation (v. 6) ntp 4.2.6p5-12.el6_9.1, ntpdate 4.2.6p5-12.el6_9.1
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2017:3071
  • Red Hat Enterprise Linux Workstation (v. 7) ntp 4.2.6p5-28.el7, ntpdate 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855
  • Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-perl 4.2.6p5-12.el6_9.1
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2017:3071
  • Red Hat Enterprise Linux Workstation Optional (v. 7) sntp 4.2.6p5-28.el7, ntp-perl 4.2.6p5-28.el7
    fixed: vendor fix “Properly monitor your ntpd instances, and auto-restart ntpd (without -g) if it stops running.” RHSA-2018:0855

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

5.24% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 6.5 CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 4.0 AV:N/AC:L/Au:S/C:N/I:N/A:P

Classification

Weakness
  • CWE-20 Improper Input Validation

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.