Public proof of conceptFix available

CVE-2016-7434

Q: Is CVE-2016-7434 actively exploited?

Active exploitation of CVE-2016-7434 has not been confirmed. Its EPSS score was 53.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

Q: What is the CVSS score for CVE-2016-7434?

CVE-2016-7434 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

A public proof of concept exists; no exploitation attested.

Published2017-01-13
Fixed in4.3.94
WeaknessCWE-20

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.

Timeline

dates in UTC

2017-01-1316:59CVE publishedNVD
2026-10-2319:23First public proof of conceptPoC-in-GitHub
2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC

Indicators tagged with this CVE, per day0 indicators over 7 days

Block these indicators

Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2016-7434?format=txt
CSV export: https://api.ismalicious.com/edl/cve/CVE-2016-7434?format=csv
TAXII collection of exploited CVEs
The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD

Ntp

Branch	Affected	Fixed in	Source
4.3	≥ 4.3.0, < 4.3.94	4.3.94	NVD
4.2	= 4.2.7	no fix published	NVD
4.2	= 4.2.8	no fix published	NVD

Hpe hpux-ntp

Branch	Affected	Fixed in	Source
—	≥ b.11.31, < c.4.2.8.2.0	c.4.2.8.2.0	NVD

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

Update Ntp to 4.3.94

Advisories and patches

support.ntp.orgMitigation · Vendor Advisory
support.ntp.orgRelease Notes · Vendor Advisory

Detection

read 2026-10-23 19:23 UTC

Nuclei template: none so far
Exploit-DB: no entry
Proof-of-concept repositories: 3 repositories, unverifiedopsxcq/exploit-CVE-2016-7434shekkbuilder/CVE-2016-7434cved-sources/cve-2016-7434

Sources

NVDCVSS 3.17.5read 2026-10-23
NVDCVSS 2.04.3read 2026-10-23
NVDweakness (CWE)CWE-20read 2026-10-23
FIRST EPSSEPSS score53.1 %read 2026-10-23
PoC-in-GitHubproof of concept3read 2026-10-23

Technical details

CVSS v3 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: 2017-01-13
Last Modified: 2026-06-17
NVD status: Modified

Frequently asked questions

What is CVE-2016-7434?

The read_mru_list function in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (crash) via a crafted mrulist query.

Is CVE-2016-7434 actively exploited?

Active exploitation of CVE-2016-7434 has not been confirmed. Its EPSS score was 53.1% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2016-7434?

CVE-2016-7434 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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