Amazon Linux AMI : ntp (ALAS-2018-1009)

critical Nessus Plugin ID 109697

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Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

Ephemeral association time spoofing additional protection

ntpd in ntp 4.2.x before 4.2.8p7 and 4.3.x before 4.3.92 allows authenticated users that know the private symmetric key to create arbitrarily-many ephemeral associations in order to win the clock selection of ntpd and modify a victim's clock via a Sybil attack. This issue exists because of an incomplete fix for CVE-2016-1549 .(CVE-2018-7170)

Interleaved symmetric mode cannot recover from bad state

ntpd in ntp 4.2.8p4 before 4.2.8p11 drops bad packets before updating the 'received' timestamp, which allows remote attackers to cause a denial of service (disruption) by sending a packet with a zero-origin timestamp causing the association to reset and setting the contents of the packet as the most recent timestamp. This issue is a result of an incomplete fix for CVE-2015-7704 .(CVE-2018-7184)

Ephemeral association time spoofing

A malicious authenticated peer can create arbitrarily-many ephemeral associations in order to win the clock selection algorithm in ntpd in NTP 4.2.8p4 and earlier and NTPsec 3e160db8dc248a0bcb053b56a80167dc742d2b74 and a5fb34b9cc89b92a8fef2f459004865c93bb7f92 and modify a victim's clock.(CVE-2016-1549)

Buffer read overrun leads information leak in ctl_getitem()

The ctl_getitem method in ntpd in ntp-4.2.8p6 before 4.2.8p11 allows remote attackers to cause a denial of service (out-of-bounds read) via a crafted mode 6 packet with a ntpd instance from 4.2.8p6 through 4.2.8p10. (CVE-2018-7182)

Unauthenticated packet can reset authenticated interleaved association

The protocol engine in ntp 4.2.6 before 4.2.8p11 allows a remote attackers to cause a denial of service (disruption) by continually sending a packet with a zero-origin timestamp and source IP address of the 'other side' of an interleaved association causing the victim ntpd to reset its association.(CVE-2018-7185)

decodearr() can write beyond its buffer limit

Buffer overflow in the decodearr function in ntpq in ntp 4.2.8p6 through 4.2.8p10 allows remote attackers to execute arbitrary code by leveraging an ntpq query and sending a response with a crafted array.(CVE-2018-7183)

Solution

Run 'yum update ntp' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2018-1009.html

Plugin Details

Severity: Critical

ID: 109697

File Name: ala_ALAS-2018-1009.nasl

Version: 1.3

Type: local

Agent: unix

Published: 5/11/2018

Updated: 4/5/2019

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.9

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

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

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:ntp, p-cpe:/a:amazon:linux:ntp-debuginfo, p-cpe:/a:amazon:linux:ntp-doc, p-cpe:/a:amazon:linux:ntp-perl, p-cpe:/a:amazon:linux:ntpdate, cpe:/o:amazon:linux

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/10/2018

Reference Information

CVE: CVE-2016-1549, CVE-2018-7170, CVE-2018-7182, CVE-2018-7183, CVE-2018-7184, CVE-2018-7185

ALAS: 2018-1009