Network Time Protocol Daemon (ntpd) 3.x / 4.x < 4.2.8p5 Denial Of Service Vulnerability

high Nessus Plugin ID 121311


The remote NTP server is affected by a denial of service vulnerability.


The version of the remote NTP server is 3.x or 4.x prior to 4.2.8p5.
It is, therefore, affected by the following vulnerability :

- he panic_gate check in NTP before 4.2.8p5 is only re-enabled after the first change to the system clock that was greater than 128 milliseconds by default, which allows remote attackers to set NTP to an arbitrary time when started with the -g option, or to alter the time by up to 900 seconds otherwise by responding to an unspecified number of requests from trusted sources, and leveraging a resulting denial of service (abort and restart).


Upgrade to NTP version 4.2.8p5 or later.

See Also

Plugin Details

Severity: High

ID: 121311

File Name: ntp_4_2_8p5.nasl

Version: 1.2

Type: remote

Family: Misc.

Published: 1/22/2019

Updated: 10/31/2019

Configuration: Enable paranoid mode

Risk Information

CVSS Score Source: CVE-2015-5300


Risk Factor: Low

Score: 3.6


Risk Factor: Medium

Base Score: 5

Temporal Score: 3.7

Vector: AV:N/AC:L/Au:N/C:N/I:N/A:P

Temporal Vector: E:U/RL:OF/RC:C


Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/a:ntp:ntp

Required KB Items: NTP/Running, Settings/ParanoidReport

Exploit Ease: No known exploits are available

Patch Publication Date: 1/7/2016

Vulnerability Publication Date: 10/8/2015

Reference Information

CVE: CVE-2015-5300