Amazon Linux 2 : cloud-init (ALAS-2021-1576)

high Nessus Plugin ID 144795

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Synopsis

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

Description

The version of cloud-init installed on the remote host is prior to 19.3-4. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2021-1576 advisory.

The default cloud-init configuration included ssh_deletekeys: 0, disabling cloud-init's deletion of ssh host keys. In some environments, this could lead to instances created by cloning a golden master or template system, sharing ssh host keys, and being able to impersonate one another or conduct man-in-the- middle attacks. (CVE-2018-10896)

A flaw was found in cloud-init, where it uses the random.choice function when creating sensitive random strings used for generating a random password in new instances. Depending on the instance configuration, a remote or local attacker may abuse this vulnerability to guess the password of the victim user.
(CVE-2020-8631)

A flaw was found in cloud-init, where it uses short passwords when generating a random password in new instances. Depending on the instance configuration, a remote or local attacker may abuse this vulnerability to guess the password of the victim user. (CVE-2020-8632)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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 cloud-init' to update your system.

Plugin Details

Severity: High

ID: 144795

File Name: al2_ALAS-2021-1576.nasl

Version: 1.3

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 1/7/2021

Updated: 12/11/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

CVSS v2

Risk Factor: Low

Base Score: 3.6

Temporal Score: 2.7

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

CVSS Score Source: CVE-2018-10896

CVSS v3

Risk Factor: High

Base Score: 7.1

Temporal Score: 6.2

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

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:cloud-init

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

Exploit Ease: No known exploits are available

Patch Publication Date: 1/5/2021

Vulnerability Publication Date: 8/1/2018

Reference Information

CVE: CVE-2018-10896, CVE-2020-8631, CVE-2020-8632

ALAS: 2021-1576

Detections

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