CentOS 7 : cloud-init (RHSA-2020:3898)

high Nessus Plugin ID 141635

Synopsis

The remote CentOS Linux host is missing one or more security updates.

Description

The remote CentOS Linux 7 host has a package installed that is affected by multiple vulnerabilities as referenced in the RHSA-2020:3898 advisory.

- The default cloud-init configuration, in cloud-init 0.6.2 and newer, 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)

- cloud-init through 19.4 relies on Mersenne Twister for a random password, which makes it easier for attackers to predict passwords, because rand_str in cloudinit/util.py calls the random.choice function.
(CVE-2020-8631)

- In cloud-init through 19.4, rand_user_password in cloudinit/config/cc_set_passwords.py has a small default pwlen value, which makes it easier for attackers to guess passwords. (CVE-2020-8632)

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

Solution

Update the affected cloud-init package.

See Also

https://access.redhat.com/errata/RHSA-2020:3898

Plugin Details

Severity: High

ID: 141635

File Name: centos_RHSA-2020-3898.nasl

Version: 1.6

Type: local

Agent: unix

Published: 10/20/2020

Updated: 10/9/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.2

Vendor

Vendor Severity: Moderate

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: p-cpe:/a:centos:centos:cloud-init, cpe:/o:centos:centos:7

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/20/2020

Vulnerability Publication Date: 8/1/2018

Reference Information

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

RHSA: 2020:3898