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Fencer Intel
medium 5.3

CVE-2016-7431 json

NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero.

published 2017-01-13 9 y ago modified 2026-06-17 4 mo ago also EUVD-2016-8284

cvss
5.3
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
8.9%
EPSS 8.9% chance of exploitation in 30 days, percentile 95%
public exploits
0
none known

Summary

NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero. NOTE: this vulnerability exists because of a CVE-2015-8138 regression.

Patch / fix

  • ntp Debian 11 1:4.2.8p9+dfsg-1

debian advisories DEBIAN-CVE-2016-7431

  • ntp SLES 11 SP3-TERADATA, SLES 11 SP3-LTSS, SLES 11 SP2-LTSS +4 more 4.2.8p9-48.9.1
  • ntp SLES for SAP 12 SP2, SLES for SAP 12 SP1, SLES for Raspberry Pi 12 SP2 +4 more 4.2.8p9-55.1
  • ntp SLES for SAP 11 SP4, SLES 11 SP4 4.2.8p9-57.2
  • ntp SLES for SAP 12, SLES 12-LTSS 4.2.8p9-46.18.1

suse advisories SUSE-SU-2017:0255-1SUSE-SU-2016:3195-1SUSE-SU-2016:3196-1SUSE-SU-2016:3193-1

  • ntp openSUSE Tumbleweed 4.2.8p9-1.1

opensuse advisories openSUSE-SU-2024:10181-1

  • ntp Arch Linux 4.2.8.p9-1

arch linux advisories AVG-79AVG-80

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-2016-7431 updated cvss 5.3

ntp: Zero Origin timestamp regression

  • 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
    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

cisa ICSA-21-159-11 updated cvss 5.3

Siemens SIMATIC NET CP 443-1 OPC UA

  • Siemens SIMATIC CP 443-1 OPC UA
    affected: mitigation, 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

8.88% chance of exploitation in the next 30 days, higher than 95% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.0 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

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.