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Fencer Intel
high 7.7

CVE-2015-7974 json

NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might a…

published 2016-01-26 10 y ago modified 2026-06-17 4 mo ago also EUVD-2015-7871

cvss
7.7
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.7%
EPSS 5.7% chance of exploitation in 30 days, percentile 93%
public exploits
0
none known

Summary

NTP 4.x before 4.2.8p6 and 4.3.x before 4.3.90 do not verify peer associations of symmetric keys when authenticating packets, which might allow remote attackers to conduct impersonation attacks via an arbitrary trusted key, aka a "skeleton key."

Patch / fix

  • ntp ntp 4.2.8, 4.3.90
  • ntp Debian 11 1:4.2.8p7+dfsg-1

debian advisories DEBIAN-CVE-2015-7974

  • ntp Ubuntu 14.04 LTS 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10
  • ntp Ubuntu 16.04 LTS 1:4.2.8p4+dfsg-3ubuntu5.3

ubuntu advisories UBUNTU-CVE-2015-7974

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 4.2.6p5-25.el7
  • sntp RHEL 7 4.2.6p5-25.el7
  • ntpdate RHEL 7 4.2.6p5-25.el7
  • ntp-perl RHEL 7 4.2.6p5-25.el7

red hat advisories RHSA-2016:2583

  • ntp SLES for SAP 12, SLES 12, SLED 12 4.2.8p8-46.8.1
  • ntp SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +3 more 4.2.8p7-44.1
  • ntp SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +3 more 4.2.8p6-41.1
  • ntp SLES 12 SP1, SLES 11 SP4, SLED 12 SP1 +2 more 4.2.8p7-11.1
  • ntp SLES for SAP 12, SLES 12, SLED 12 4.2.8p6-46.5.2
  • yast2-ntp-client SLES for SAP 12, SLES 12, SLED 12 +1 more 3.1.12.4-8.2
  • ntp SLES 12 SP1, SLES 11 SP4, SLED 12 SP1 +2 more 4.2.8p6-8.2
  • yast2-ntp-client SLES for SAP 12 SP1, SLES 12 SP1, SLED 12 SP1 +1 more 3.1.22-6.2

suse advisories SUSE-SU-2016:1568-1SUSE-SU-2016:1471-1SUSE-SU-2016:1311-1SUSE-SU-2016:1291-1SUSE-SU-2016:1278-1SUSE-SU-2016:1247-1

  • 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-2015-7974 updated cvss 3.6

ntp: missing key check allows impersonation between authenticated peers (VU#357792)

  • Red Hat Enterprise Linux 5 ntp Red Hat Enterprise Linux 6 ntp, ntpdate, ntp-perl
    affected: no fix planned “Will not fix”
  • Red Hat Enterprise Linux Client (v. 7) ntp 4.2.6p5-25.el7, ntpdate 4.2.6p5-25.el7 Red Hat Enterprise Linux Client Optional (v. 7) sntp 4.2.6p5-25.el7, ntp-perl 4.2.6p5-25.el7 Red Hat Enterprise Linux ComputeNode (v. 7) ntp 4.2.6p5-25.el7, ntpdate 4.2.6p5-25.el7 Red Hat Enterprise Linux ComputeNode Optional (v. 7) sntp 4.2.6p5-25.el7, ntp-perl 4.2.6p5-25.el7 Red Hat Enterprise Linux Server (v. 7) ntp 4.2.6p5-25.el7, ntpdate 4.2.6p5-25.el7 Red Hat Enterprise Linux Server Optional (v. 7) sntp 4.2.6p5-25.el7, ntp-perl 4.2.6p5-25.el7
    +2 more products
    Red Hat Enterprise Linux Workstation (v. 7) ntp 4.2.6p5-25.el7, ntpdate 4.2.6p5-25.el7 Red Hat Enterprise Linux Workstation Optional (v. 7) sntp 4.2.6p5-25.el7, ntp-perl 4.2.6p5-25.el7
    fixed: vendor fix RHSA-2016:2583

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

cisa ICSA-21-103-11 updated cvss 7.7

Siemens TIM 4R-IE Devices

  • Siemens SIPLUS NET TIM 4R-IE (6AG1800-4BA00-7AA0) Siemens SIPLUS NET TIM 4R-IE DNP3 (6AG1803-4BA00-7AA0) Siemens TIM 4R-IE (6NH7800-4BA00) Siemens TIM 4R-IE DNP3 (6NH7803-4BA00-0AA0)
    affected: workaround, no fix planned

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

Exploit prediction

5.66% chance of exploitation in the next 30 days, higher than 93% of all scored CVEs (FIRST EPSS, 2026-11-09).

Exploits and checks

  • talosintel.com http://www.talosintel.com/reports/TALOS-2016-0071/ referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.7 CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N
NVD 2.0 4.0 AV:N/AC:L/Au:S/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.