CVE-2016-7431

Publication date 13 January 2017

Last updated 25 August 2025

Ubuntu priority

Cvss 3 Severity Score

Description

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.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
ntp	17.04 zesty	Not affected
	16.10 yakkety	Fixed 1:4.2.8p8+dfsg-1ubuntu2.1
	16.04 LTS xenial	Not affected
	14.04 LTS trusty	Not affected
	12.04 LTS precise	Not affected

Notes

mdeslaur

ntp-4.2.8p8 and ntp-4.3.93

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package	Patch details
ntp	Upstream: http://bk1.ntp.org/ntp-stable/?PAGE=cset&REV=57ff44d0W6suoUHdd2ZvRM3z87j2QA

Severity score breakdown

CVSS version: CVSS v3.0

Base score 5.3 · Medium

Base metrics

Parameter	Value
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality impact	None
Integrity impact	Low
Availability impact	None

Scores

Parameter	Value
Base score	5.3 · Medium
Exploitability score	-
Impact score	-

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

References

Related Ubuntu Security Notices (USN)

USN-3349-1
NTP vulnerabilities
5 July 2017

Other references

https://www.cve.org/CVERecord?id=CVE-2016-7431