FreeBSD : ntp -- Crafted null dereference attack from a trusted source with an authenticated mode 6 packet (c2576e14-36e2-11e9-9eda-206a8a720317)

high Nessus Plugin ID 122685

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Synopsis

The remote FreeBSD host is missing a security-related update.

Description

Network Time Foundation reports :

A crafted malicious authenticated mode 6 (ntpq) packet from a permitted network address can trigger a NULL pointer dereference, crashing ntpd.

Note that for this attack to work, the sending system must be on an address that the target's ntpd accepts mode 6 packets from, and must use a private key that is specifically listed as being used for mode 6 authorization.

Impact: The ntpd daemon can crash due to the NULL pointer dereference, causing a denial of service.

Mitigation :

- Use restrict noquery to limit addresses that can send mode 6 queries.

- Limit access to the private controlkey in ntp.keys.

- Upgrade to 4.2.8p13, or later.

Solution

Update the affected package.

Plugin Details

Severity: High

ID: 122685

File Name: freebsd_pkg_c2576e1436e211e99eda206a8a720317.nasl

Version: 1.8

Type: local

Family: FreeBSD Local Security Checks

Published: 3/8/2019

Updated: 6/14/2024

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 5

Temporal Score: 3.9

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P

CVSS Score Source: CVE-2019-8936

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:ntp, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 3/7/2019

Vulnerability Publication Date: 1/15/2019

Reference Information

CVE: CVE-2019-8936

FreeBSD: SA-19:04.ntp

IAVA: 2019-A-0078-S

Detections

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