Amazon Linux 2 : amazon-ssm-agent (ALAS-2024-2645)

critical Nessus Plugin ID 208102

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Synopsis

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

Description

The version of amazon-ssm-agent installed on the remote host is prior to 3.3.859.0-1. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2024-2645 advisory.

An attacker may cause an HTTP/2 endpoint to read arbitrary amounts of header data by sending an excessive number of CONTINUATION frames. Maintaining HPACK state requires parsing and processing all HEADERS and CONTINUATION frames on a connection. When a request's headers exceed MaxHeaderBytes, no memory is allocated to store the excess headers, but they are still parsed. This permits an attacker to cause an HTTP/2 endpoint to read arbitrary amounts of header data, all associated with a request which is going to be rejected. These headers can include Huffman-encoded data which is significantly more expensive for the receiver to decode than for an attacker to send. The fix sets a limit on the amount of excess header frames we will process before closing a connection. (CVE-2023-45288)

The various Is methods (IsPrivate, IsLoopback, etc) did not work as expected for IPv4-mapped IPv6 addresses, returning false for addresses which would return true in their traditional IPv4 forms.
(CVE-2024-24790)

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 amazon-ssm-agent' to update your system.

Plugin Details

Severity: Critical

ID: 208102

File Name: al2_ALAS-2024-2645.nasl

Version: 1.2

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 10/3/2024

Updated: 10/4/2024

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

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-2024-24790

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:amazon-ssm-agent

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: 9/25/2024

Vulnerability Publication Date: 4/4/2024

Reference Information

CVE: CVE-2023-45288, CVE-2024-24790

IAVB: 2024-B-0032-S, 2024-B-0071-S

Detections

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