Amazon Linux 2023 : amazon-ssm-agent (ALAS2023-2023-388)

critical Nessus Plugin ID 183829

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Synopsis

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

Description

It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2023-2023-388 advisory.

The x/crypto/ssh package before 0.0.0-20211202192323-5770296d904e of golang.org/x/crypto allows an attacker to panic an SSH server. (CVE-2021-43565)

A broken cryptographic algorithm flaw was found in golang.org/x/crypto/ssh. This issue causes a client to fail authentification with RSA keys to servers that reject signature algorithms based on SHA-2, enabling an attacker to crash the server, resulting in a loss of availability. (CVE-2022-27191)

In net/http in Go before 1.18.6 and 1.19.x before 1.19.1, attackers can cause a denial of service because an HTTP/2 connection can hang during closing if shutdown were preempted by a fatal error. (CVE-2022-27664)

http2/hpack: avoid quadratic complexity in hpack decoding (CVE-2022-41723)

Templates did not properly consider backticks (`) as Javascript string delimiters, and as such didnot escape them as expected. Backticks are used, since ES6, for JS template literals. If a templatecontained a Go template action within a Javascript template literal, the contents of the action couldbe used to terminate the literal, injecting arbitrary Javascript code into the Go template. (CVE-2023-24538)

The HTTP/1 client does not fully validate the contents of the Host header. A maliciously crafted Host header can inject additional headers or entire requests. With fix, the HTTP/1 client now refuses to send requests containing an invalid Request.Host or Request.URL.Host value. (CVE-2023-29406)

Extremely large RSA keys in certificate chains can cause a client/server to expend significant CPU time verifying signatures. With fix, the size of RSA keys transmitted during handshakes is restricted to <= 8192 bits. Based on a survey of publicly trusted RSA keys, there are currently only three certificates in circulation with keys larger than this, and all three appear to be test certificates that are not actively deployed. It is possible there are larger keys in use in private PKIs, but we target the web PKI, so causing breakage here in the interests of increasing the default safety of users of crypto/tls seems reasonable. (CVE-2023-29409)

Text nodes not in the HTML namespace are incorrectly literally rendered, causing text which should be escaped to not be. This could lead to an XSS attack. (CVE-2023-3978)

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 'dnf update amazon-ssm-agent --releasever 2023.2.20231018' or or 'dnf update --advisory ALAS2023-2023-388 --releasever 2023.2.20231018' to update your system.

Plugin Details

Severity: Critical

ID: 183829

File Name: al2023_ALAS2023-2023-388.nasl

Version: 1.2

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 10/24/2023

Updated: 9/11/2025

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: Medium

Base Score: 4.3

Temporal Score: 3.2

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

CVSS Score Source: CVE-2022-27191

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

CVSS Score Source: CVE-2023-24538

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:amazon-ssm-agent-debuginfo, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:amazon-ssm-agent, p-cpe:/a:amazon:linux:amazon-ssm-agent-debugsource

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/12/2023

Vulnerability Publication Date: 4/7/2022

Reference Information

CVE: CVE-2021-43565, CVE-2022-27191, CVE-2022-27664, CVE-2022-41723, CVE-2023-24538, CVE-2023-29406, CVE-2023-29409, CVE-2023-3978

IAVB: 2023-B-0012-S, 2023-B-0022-S

Detections

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