Severity: Normal
Title: PyYAML: Arbitrary Code Execution
Date: February 26, 2024
Bugs: #766228
ID: 202402-33

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Synopsis
========

A vulnerability has been found in PyYAML which can lead to arbitrary
code execution.

Background
==========

PyYAML is a YAML parser and emitter for Python.

Affected packages
=================

Package Vulnerable Unaffected
----------------- ------------ ------------
dev-python/pyyaml < 5.4 >= 5.4

Description
===========

A vulnerability has been discovered in PyYAML. Please review the CVE
identifier referenced below for details.

Impact
======

A vulnerability was discovered in the PyYAML library, where it is
susceptible to arbitrary code execution when it processes untrusted YAML
files through the full_load method or with the FullLoader loader.
Applications that use the library to process untrusted input may be
vulnerable to this flaw. This flaw allows an attacker to execute
arbitrary code on the system by abusing the python/object/new
constructor. This flaw is due to an incomplete fix for CVE-2020-1747.

Workaround
==========

There is no known workaround at this time.

Resolution
==========

All PyYAML users should upgrade to the latest version:

# emerge --sync
# emerge --ask --oneshot --verbose ">=dev-python/pyyaml-5.4"

References
==========

[ 1 ] CVE-2020-14343
https://nvd.nist.gov/vuln/detail/CVE-2020-14343

Availability
============

This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:

https://security.gentoo.org/glsa/202402-33

Concerns?
=========

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users' machines is of utmost
importance to us. Any security concerns should be addressed to
[email protected] or alternatively, you may file a bug at
https://bugs.gentoo.org.

License
=======

Copyright 2024 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).

The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.

https://creativecommons.org/licenses/by-sa/2.5