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Fencer Intel
low 1.8

CVE-2015-1798 json

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p2 requires a correct MAC only if the MAC f…

published 2015-04-08 11 y ago modified 2026-06-17 4 mo ago also EUVD-2015-1923

cvss
1.8
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.2%
EPSS 2.2% chance of exploitation in 30 days, percentile 82%
public exploits
0
none known

Summary

The symmetric-key feature in the receive function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p2 requires a correct MAC only if the MAC field has a nonzero length, which makes it easier for man-in-the-middle attackers to spoof packets by omitting the MAC.

Patch / fix

  • ntp Debian 11 1:4.2.6.p5+dfsg-6

debian advisories DEBIAN-CVE-2015-1798

  • ntp Ubuntu 14.04 LTS 1:4.2.6.p5+dfsg-3ubuntu2.14.04.3

ubuntu advisories UBUNTU-CVE-2015-1798

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 4.2.6p5-22.el7
  • sntp RHEL 7 4.2.6p5-22.el7
  • ntpdate RHEL 7 4.2.6p5-22.el7
  • ntp-perl RHEL 7 4.2.6p5-22.el7
  • ntp RHEL 6 4.2.6p5-5.el6
  • ntpdate RHEL 6 4.2.6p5-5.el6
  • ntp-perl RHEL 6 4.2.6p5-5.el6

red hat advisories RHSA-2015:2231RHSA-2015:1459

  • ntp SLES for SAP 12, SLES 12, SLED 12 4.2.6p5-44.1

suse advisories SUSE-SU-2015:0865-1

  • ntp openSUSE Tumbleweed 4.2.8p9-1.1

opensuse advisories openSUSE-SU-2024:10181-1

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-2015-1798 updated cvss 2.6

ntp: ntpd accepts unauthenticated packets with symmetric key crypto

  • Red Hat Enterprise Linux Client (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7 Red Hat Enterprise Linux Client Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7 Red Hat Enterprise Linux ComputeNode (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Desktop (v. 6) ntp 4.2.6p5-5.el6, ntpdate 4.2.6p5-5.el6 Red Hat Enterprise Linux Desktop Optional (v. 6) ntp-perl 4.2.6p5-5.el6 Red Hat Enterprise Linux HPC Node (v. 6) ntp 4.2.6p5-5.el6, ntpdate 4.2.6p5-5.el6 Red Hat Enterprise Linux HPC Node Optional (v. 6) ntp-perl 4.2.6p5-5.el6 Red Hat Enterprise Linux Server (v. 6) ntp 4.2.6p5-5.el6, ntpdate 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Server (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Server Optional (v. 6) ntp-perl 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Server Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Workstation (v. 6) ntp 4.2.6p5-5.el6, ntpdate 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
  • Red Hat Enterprise Linux Workstation (v. 7) ntp 4.2.6p5-22.el7, ntpdate 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux Workstation Optional (v. 6) ntp-perl 4.2.6p5-5.el6
    fixed: vendor fix RHSA-2015:1459
show 2 more
  • Red Hat Enterprise Linux Workstation Optional (v. 7) sntp 4.2.6p5-22.el7, ntp-perl 4.2.6p5-22.el7
    fixed: vendor fix RHSA-2015:2231
  • Red Hat Enterprise Linux 5 ntp
    not affected: vulnerable code not present

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

2.24% chance of exploitation in the next 30 days, higher than 82% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 1.8 AV:A/AC:H/Au:N/C:N/I:P/A:N

Classification

Weakness

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.