Amazon Linux 2023 : rsyslog, rsyslog-crypto, rsyslog-elasticsearch (ALAS2023-2026-3157)

critical Nessus Plugin ID 365224

Synopsis

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

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-3157 advisory.

rsyslog's omfile dynaFile facility intentionally allows templates to generate flexible output paths. This supports valid deployments that route logs into different directories or use dynamically generated file names.

A deployment becomes unsafe when a dynaFile template uses a value influenced by untrusted input as a path component without explicit secure-path handling. In that configuration, the rendered path can escape the operator's intended log directory.

This is not limited to the RFC5424 HOSTNAME field. Any untrusted value that reaches a dynaFile path component can create the condition.

An attacker who can influence such a value may cause rsyslog to create or append to files outside the intended output directory, subject to rsyslog's effective privileges and host confinement.

The practical result depends on the deployment. Mandatory access controls, systemd sandboxing, filesystem permissions, the configured input modules, and the selected output template can all limit or prevent impact. A code-execution outcome requires additional, deployment-specific conditions and is not representative of default distribution configurations.

Default Debian and Ubuntu configurations do not enable a network input and a dynaFile action of this form.
The affected configuration must be explicitly deployed. (CVE-2026-92709)

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 rsyslog --releasever 2023.12.20261012' or or 'dnf update --advisory ALAS2023-2026-3157 --releasever 2023.12.20261012' to update your system.

See Also

https://alas.aws.amazon.com//AL2023/ALAS2023-2026-3157.html

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

https://explore.alas.aws.amazon.com/CVE-2026-92709.html

Plugin Details

Severity: Critical

ID: 365224

File Name: al2023_ALAS2023-2026-3157.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/12/2026

Updated: 10/12/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.47

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 5.5

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

CVSS Score Source: CVE-2026-92709

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

Vulnerability Information

CPE: cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:rsyslog-crypto-debuginfo, p-cpe:/a:amazon:linux:rsyslog-crypto, p-cpe:/a:amazon:linux:rsyslog-debuginfo, p-cpe:/a:amazon:linux:rsyslog-debugsource, p-cpe:/a:amazon:linux:rsyslog-doc, p-cpe:/a:amazon:linux:rsyslog-elasticsearch-debuginfo, p-cpe:/a:amazon:linux:rsyslog-elasticsearch, p-cpe:/a:amazon:linux:rsyslog-logrotate, p-cpe:/a:amazon:linux:rsyslog-mmaudit-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmaudit, p-cpe:/a:amazon:linux:rsyslog-mmfields-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmfields, p-cpe:/a:amazon:linux:rsyslog-mmjsonparse-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmjsonparse, p-cpe:/a:amazon:linux:rsyslog-mmkubernetes-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmkubernetes, p-cpe:/a:amazon:linux:rsyslog-mmnormalize-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmnormalize, p-cpe:/a:amazon:linux:rsyslog-mmtaghostname-debuginfo, p-cpe:/a:amazon:linux:rsyslog-mmtaghostname, p-cpe:/a:amazon:linux:rsyslog-openssl-debuginfo, p-cpe:/a:amazon:linux:rsyslog-openssl, p-cpe:/a:amazon:linux:rsyslog

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/12/2026

Vulnerability Publication Date: 10/12/2026

Reference Information

CVE: CVE-2026-92709