ntpd in NTP before 4.2.8p8 allows remote attackers to cause a denial of service (daemon crash) via a crypto-NAK packet. NOTE: this vulnerability exists because of an incorrect fix for CVE-2016-1547.
CVE-2016-4957
Score elevated to 7.9 because EPSS predicts 45% probability of exploitation within the next 30 days (top 1.3% of all CVEs). NVD baseline CVSS 7.5 retained for reference. Confidence: see factors.
- High severity, but no confirmed exploitation yet
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 7.5
- EG Score
- 7.9(high)
- EG Risk
- 58(Track)EG Risk 58/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity79% × 45%Exploitation45% × 40%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 45%
- EPSS %ILE
- 99%
- KEV
- Not listed
Published
July 5, 2016
Last Modified
June 17, 2026
References (26)
- cve@mitrehttp://bugs.ntp.org/3046
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00023.html
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00024.html
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00028.html
- cve@mitrehttp://lists.opensuse.org/opensuse-security-announce/2016-06/msg00040.html
- cve@mitrehttp://support.ntp.org/bin/view/Main/NtpBug3046
- cve@mitrehttp://support.ntp.org/bin/view/Main/SecurityNotice
- cve@mitrehttp://www.kb.cert.org/vuls/id/321640
- cve@mitrehttp://www.oracle.com/technetwork/topics/security/bulletinapr2016-2952098.html
- cve@mitrehttp://www.securitytracker.com/id/1036037
- cve@mitrehttps://security.FreeBSD.org/advisories/FreeBSD-SA-16:24.ntp.asc
- cve@mitrehttps://security.gentoo.org/glsa/201607-15
- af854a3a-2127-422b-91ae-364da2661108http://bugs.ntp.org/3046
- af854a3a-2127-422b-91ae-364da2661108http://lists.opensuse.org/opensuse-security-announce/2016-06/msg00018.html
Affected Packages
(1 across 1 ecosystem)
Debian:11(1)
| Package | Vulnerable range | Fixed in | Dependents |
|---|---|---|---|
| ntp | — | 1:4.2.8p8+dfsg-1 | — |
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 15× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
Showing the most recent 100 of 121 total refreshes for this CVE.
- 2026-09-18 23:23 UTCOSV refresh
- 2026-09-18 19:22 UTCEPSS rescore
- 2026-09-17 19:21 UTCEPSS rescore
- 2026-09-15 03:05 UTCEPSS rescore
- 2026-09-12 14:55 UTCEPSS rescore
- 2026-09-10 09:26 UTCEPSS rescore
- 2026-09-07 15:56 UTCEPSS rescore
- 2026-09-04 13:56 UTCEPSS rescore
- 2026-09-02 14:07 UTCEPSS rescore
- 2026-08-31 03:02 UTCOSV refresh
- 2026-08-30 19:12 UTCEPSS rescore
- 2026-08-27 14:20 UTCEPSS rescore
- 2026-08-26 14:41 UTCEPSS rescore
- 2026-08-25 13:44 UTCEPSS rescore
- 2026-08-21 23:44 UTCEPSS rescore
- 2026-08-19 16:59 UTCEPSS rescore
- 2026-08-18 13:43 UTCEPSS rescore
- 2026-08-17 13:42 UTCEPSS rescore
- 2026-08-16 14:51 UTCEPSS rescore
- 2026-08-16 02:09 UTCEPSS rescore
- 2026-08-15 01:25 UTCEPSS rescore
- 2026-08-14 11:15 UTCOSV refresh
- 2026-08-12 13:46 UTCEPSS rescore
- 2026-08-11 13:36 UTCEPSS rescore
- 2026-08-08 16:32 UTCEPSS rescore
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- 2026-08-06 13:42 UTCEPSS rescore
- 2026-08-01 04:11 UTCEPSS rescore
- 2026-07-30 16:23 UTCEPSS rescore
- 2026-07-30 01:26 UTCEPSS rescore
- 2026-07-29 22:07 UTCOSV refresh
- 2026-07-28 15:31 UTCEPSS rescore
- 2026-07-26 14:50 UTCEPSS rescore
- 2026-07-25 14:13 UTCEPSS rescore
- 2026-07-23 14:14 UTCEPSS rescore
- 2026-07-23 01:23 UTCEG score recompute▲ 0.40
- 2026-07-22 22:02 UTCEG score recompute
- 2026-07-22 14:04 UTCEPSS rescore
- 2026-07-21 15:21 UTCEPSS rescore
- 2026-07-21 15:21 UTCEPSS rescore
- 2026-07-20 17:03 UTCEPSS rescore
- 2026-07-19 14:27 UTCEPSS rescore
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- 2026-07-18 10:00 UTCEPSS rescore
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- 2026-07-16 16:59 UTCEPSS rescore
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- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-15 16:54 UTCEPSS rescore
- 2026-07-13 22:26 UTCEPSS rescore
- 2026-07-13 06:09 UTCEPSS rescore
- 2026-07-12 09:07 UTCOSV refresh
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-12 05:43 UTCEPSS rescore
- 2026-07-11 08:23 UTCEPSS rescore
- 2026-07-09 19:05 UTCEPSS rescore
- 2026-07-08 15:10 UTCEPSS rescore
- 2026-07-06 16:24 UTCEPSS rescore
- 2026-07-06 16:24 UTCEPSS rescore
- 2026-07-06 02:20 UTCEPSS rescore
- 2026-07-06 02:20 UTCEPSS rescore
- 2026-07-05 02:27 UTCEPSS rescore
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-06-28 04:53 UTCEPSS rescore
- 2026-06-27 03:05 UTCEPSS rescore
- 2026-06-27 03:05 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-25 13:47 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-24 14:02 UTCEPSS rescore
- 2026-06-23 21:30 UTCEPSS rescore
- 2026-06-23 14:30 UTCOSV refresh
- 2026-06-22 14:23 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 14:54 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-21 01:57 UTCEPSS rescore
- 2026-06-18 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-17 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-16 17:50 UTCEPSS rescore
- 2026-06-15 17:45 UTCEPSS rescore
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-13 22:57 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-12 23:09 UTCEPSS rescore
- 2026-06-10 22:15 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-06 17:59 UTCOSV refresh
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-05 06:08 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-04 13:10 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-05-31 00:14 UTCEPSS rescore
Related CVEs(same CWE)
Frequently asked(5)
What is CVE-2016-4957?
When was CVE-2016-4957 disclosed?
Is CVE-2016-4957 actively exploited?
What is the CVSS score of CVE-2016-4957?
How do I remediate CVE-2016-4957?
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2016-4957
Is Your Infrastructure Affected by CVE-2016-4957?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.