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Fencer Intel
medium 6.5

CVE-2015-7973 json

NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks…

published 2017-01-30 9 y ago modified 2026-06-17 4 mo ago also EUVD-2015-7870

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.4%
EPSS 3.4% chance of exploitation in 30 days, percentile 88%
public exploits
0
none known

Summary

NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.

Patch / fix

  • ntp ntp 4.2.8, 4.3.90
  • freebsd freebsd 10.1
  • ntp Debian 11 1:4.2.8p7+dfsg-1

debian advisories DEBIAN-CVE-2015-7973

  • 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-2015-7973

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 SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +3 more 4.2.8p6-41.1
  • 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
  • yast2-ntp-client SLES 11 SP2-LTSS 2.17.14.1-1.12.1

suse advisories SUSE-SU-2016:1311-1SUSE-SU-2016:1247-1SUSE-SU-2016:1175-1SUSE-SU-2016:1177-1

  • 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-2015-7973 updated cvss 4.3

ntp: replay attack on authenticated broadcast mode

  • 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: workaround, no fix planned “Do not use NTP's broadcast mode by not configuring the "broadcast" directive in the ntp.conf file.”

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 6.5

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

3.35% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H
NVD 2.0 5.8 AV:N/AC:M/Au:N/C:N/I:P/A:P

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.