Amazon Linux 2023 : openssh, openssh-clients, openssh-keycat (ALAS2023-2023-273)

high Nessus Plugin ID 179760

Synopsis

The remote Amazon Linux 2023 host is missing a security update.

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2023-273 advisory.

The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if the target user's ssh-agent is forwarded to an attacker-controlled system (the code in /usr/lib is not necessarily safe for loading into ssh-agent). Exploitation can also be prevented by starting ssh-agent with an empty PKCS#11/FIDO allowlist (ssh-agent -P '') or by configuring an allowlist that contains only specific provider libraries. NOTE: this issue exists because of an incomplete fix for CVE-2016-10009. (CVE-2023-38408)

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

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

Solution

Run 'dnf update openssh --releasever 2023.1.20230809' to update your system.

See Also

https://alas.aws.amazon.com/AL2023/ALAS-2023-273.html

https://alas.aws.amazon.com/cve/html/CVE-2023-38408.html

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

Plugin Details

Severity: High

ID: 179760

File Name: al2023_ALAS2023-2023-273.nasl

Version: 1.3

Type: local

Agent: unix

Published: 8/14/2023

Updated: 12/11/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2023-38408

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

CVSS v4

Risk Factor: High

Base Score: 8.9

Threat Score: 8.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:openssh-clients, p-cpe:/a:amazon:linux:openssh-clients-debuginfo, p-cpe:/a:amazon:linux:openssh-keycat, p-cpe:/a:amazon:linux:pam_ssh_agent_auth, p-cpe:/a:amazon:linux:openssh-debugsource, p-cpe:/a:amazon:linux:openssh-keycat-debuginfo, p-cpe:/a:amazon:linux:openssh-server, p-cpe:/a:amazon:linux:openssh-server-debuginfo, p-cpe:/a:amazon:linux:pam_ssh_agent_auth-debuginfo, p-cpe:/a:amazon:linux:openssh, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:openssh-debuginfo

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: 8/3/2023

Vulnerability Publication Date: 7/20/2023

Reference Information

CVE: CVE-2023-38408

IAVA: 2023-A-0377-S