Improper input validation in NTP

CVE-2016-1547

An off-path attacker can cause a preemptible client association to be demobilized in NTP 4.2.8p4 and earlier and NTPSec a5fb34b9cc89b92a8fef2f459004865c93bb7f92 by sending a crypto NAK packet to a victim client with a spoofed source address of an existing associated peer. This is true even if authentication is enabled.

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.

EPSS exploit prediction

EPSS: 0.051 (92.1th percentile), scored .

Low probability of exploitation in the next 30 days, but still tracked. 92nd percentile — 92.1% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2016-1547: held from 0.051 to 0.051.

EPSS over last 30 days · oldest: 0.051 · newest: 0.051 · change: 0.000

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2016-1547?
CVE-2016-1547 is a medium-severity vulnerability in NTP, classified under Improper Input Validation. CVSS score: 5.3/10. Published 2017-01-06.
How severe is CVE-2016-1547?
Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2016-1547 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.