CVE-2016-4957
HIGHEPSS 99th pctlDescription
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.
How to fix
TridentStack Control can deploy fixes like this automatically across your Windows, macOS, and Linux fleet. See how it works
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Very high risk: more likely to be exploited than 99% of all known CVEs.
References
Related Vulnerabilities
Other CWE-476 (NULL Pointer Dereference) vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2023-21758 | High | 7.5 | 93% | - | Fix |
| CVE-2023-21547 | High | 7.5 | 89% | - | Fix |
| CVE-2014-3470 | Medium | 4.3 | 86% | - | Fix |
| CVE-2021-44224 | High | 8.2 | 82% | - | Fix |
| CVE-2016-0742 | High | 7.5 | 82% | - | Fix |
| CVE-2009-1386 | Medium | 5.0 | 80% | - | Fix |
Common questions
How do I fix CVE-2016-4957?
Upgrade ntp on debian 11 to 1:4.2.8p8+dfsg-1 or later.
Is CVE-2016-4957 being actively exploited?
Not that we know of. CVE-2016-4957 is not in the CISA Known Exploited Vulnerabilities catalog. Its EPSS score of 44.9% is the estimated probability that it will be exploited in the next 30 days. That is higher than 99% of all scored CVEs.
How severe is CVE-2016-4957?
CVE-2016-4957 has a CVSS v3 base score of 7.5, rated high. CVSS rates the technical impact if the vulnerability is exploited, not how likely that is, so weigh it alongside the exploit-prediction score when you decide what to patch first.
What does CVE-2016-4957 affect?
Published advisories record a fix for ntp (Debian). Only products with a sourced advisory are listed, so treat this as what we can cite rather than a complete inventory.
Embed a live status badge for CVE-2016-4957
Markdown
[](https://tridentstack.com/cve/CVE-2016-4957)HTML
<a href="https://tridentstack.com/cve/CVE-2016-4957"><img src="https://tridentstack.com/cve/badge/CVE-2016-4957.svg" alt="CVE-2016-4957"></a>Find and fix vulnerabilities across your fleet
TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.
This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-05-06.