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Amazon Linux 2023 : policycoreutils, policycoreutils-dbus, policycoreutils-devel (ALAS2023-2026-1663)

critical Nessus Plugin ID 315644

Synopsis

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

Description

It is, therefore, affected by a vulnerability as referenced in the ALAS2023-2026-1663 advisory.

 An undocumented and unsafe feature in the PLY (Python Lex-Yacc) library 3.11 allows Remote Code Execution (RCE) via the `picklefile` parameter in the `yacc()` function. This parameter accepts a `.pkl` file that is deserialized with `pickle.load()` without validation. Because `pickle` allows execution of embedded code via `__reduce__()`, an attacker can achieve code execution by passing a malicious pickle file. The parameter is not mentioned in official documentation or the GitHub repository, yet it is active in the PyPI version. This introduces a stealthy backdoor and persistence risk. (CVE-2025-56005)

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 policycoreutils --releasever 2023.11.20260511' or or 'dnf update --advisory ALAS2023-2026-1663 --releasever 2023.11.20260511' to update your system.

See Also

https://alas.aws.amazon.com//AL2023/ALAS2023-2026-1663.html

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

https://explore.alas.aws.amazon.com/CVE-2025-56005.html

Plugin Details

Severity: Critical

ID: 315644

File Name: al2023_ALAS2023-2026-1663.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 5/20/2026

Updated: 5/20/2026

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: 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-2025-56005

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: p-cpe:/a:amazon:linux:policycoreutils-newrole-debuginfo, cpe:/o:amazon:linux:2023, p-cpe:/a:amazon:linux:python3-policycoreutils, p-cpe:/a:amazon:linux:policycoreutils-restorecond-debuginfo, p-cpe:/a:amazon:linux:policycoreutils-gui, p-cpe:/a:amazon:linux:policycoreutils-dbus, p-cpe:/a:amazon:linux:policycoreutils-python-utils, p-cpe:/a:amazon:linux:policycoreutils-debugsource, p-cpe:/a:amazon:linux:policycoreutils, p-cpe:/a:amazon:linux:policycoreutils-restorecond, p-cpe:/a:amazon:linux:policycoreutils-newrole, p-cpe:/a:amazon:linux:policycoreutils-devel-debuginfo, p-cpe:/a:amazon:linux:policycoreutils-debuginfo, p-cpe:/a:amazon:linux:policycoreutils-devel

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: 5/14/2026

Vulnerability Publication Date: 1/20/2026

Reference Information

CVE: CVE-2025-56005