Amazon Linux 2 : dnsmasq (ALASDNSMASQ-2024-002)

high Nessus Plugin ID 193452

Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of dnsmasq installed on the remote host is prior to 2.90-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2DNSMASQ-2024-002 advisory.

- Certain DNSSEC aspects of the DNS protocol (in RFC 4033, 4034, 4035, 6840, and related RFCs) allow remote attackers to cause a denial of service (CPU consumption) via one or more DNSSEC responses, aka the KeyTrap issue. One of the concerns is that, when there is a zone with many DNSKEY and RRSIG records, the protocol specification implies that an algorithm must evaluate all combinations of DNSKEY and RRSIG records. (CVE-2023-50387)

- The Closest Encloser Proof aspect of the DNS protocol (in RFC 5155 when RFC 9276 guidance is skipped) allows remote attackers to cause a denial of service (CPU consumption for SHA-1 computations) via DNSSEC responses in a random subdomain attack, aka the NSEC3 issue. The RFC 5155 specification implies that an algorithm must perform thousands of iterations of a hash function in certain situations. (CVE-2023-50868)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update dnsmasq' to update your system.

See Also

https://alas.aws.amazon.com/AL2/ALASDNSMASQ-2024-002.html

https://alas.aws.amazon.com/cve/html/CVE-2023-50387.html

https://alas.aws.amazon.com/cve/html/CVE-2023-50868.html

https://alas.aws.amazon.com/faqs.html

Plugin Details

Severity: High

ID: 193452

File Name: al2_ALASDNSMASQ-2024-002.nasl

Version: 1.0

Type: local

Agent: unix

Published: 4/18/2024

Updated: 4/18/2024

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 5.1

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2023-50387

CVSS v3

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: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:dnsmasq, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:dnsmasq-debuginfo, p-cpe:/a:amazon:linux:dnsmasq-utils

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

Exploit Ease: No known exploits are available

Patch Publication Date: 4/10/2024

Vulnerability Publication Date: 2/13/2024

Reference Information

CVE: CVE-2023-50387, CVE-2023-50868