CVE-2016-4954

Publication date 4 July 2016

Last updated 25 August 2025

Ubuntu priority

Low

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Description

The process_packet function in ntp_proto.c in ntpd in NTP 4.x before 4.2.8p8 allows remote attackers to cause a denial of service (peer-variable modification) by sending spoofed packets from many source IP addresses in a certain scenario, as demonstrated by triggering an incorrect leap indication.

Status

Package Ubuntu Release Status
ntp 17.04 zesty
Not affected
16.10 yakkety
Not affected
16.04 LTS xenial
Fixed 1:4.2.8p4+dfsg-3ubuntu5.3
15.10 wily Ignored end of life
14.04 LTS trusty
Fixed 1:4.2.6.p5+dfsg-3ubuntu2.14.04.10
12.04 LTS precise
Fixed 1:4.2.6.p3+dfsg-1ubuntu3.11

Patch details

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

Package Patch details
ntp

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Scope Unchanged
Confidentiality None
Integrity impact None
Availability impact High
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References

Related Ubuntu Security Notices (USN)

Other references