ROS-2-491

2.491 PyYAML parser vulnerability (CVE-2020-14343)

1. Vulnerability description:

A vulnerability in the PyYAML parser, is related to insufficient validation of user input when processing unreliable YAML files using the full_load method or the FullLoader loader. Exploitation of the vulnerability could allow an attacker acting remotely to pass specially crafted input to an application and execute arbitrary code on the system.Identifier of the Information Security Threat Data Bank of the FSTEC of Russia: BDU:2021-03488

2. Possible measures to eliminate the vulnerability

Prohibit using PyYAML in projects or - install security updates for the package: PyYAML**Installing updates is possible in the following ways:**a) if the computer with the installed OS version has access to the vendor’s official repository, run the update as administrator with the command:# yum updateAfter the list of updated packages is displayed, agree to apply the updates by pressing the Y key on the keyboard. Wait until the update installation is complete and make sure that there are no errors during its installation.b)If the computer with the installed OS version does not have access to the vendor’s official repository, you should perform the following actions: - download the updated package (with dependencies if necessary): http://repo.red-soft.ru/redos/7.2c/x86_64/updates/python2-pyyaml-5.4.1-1.el7.x86_64.rpm Check the integrity and authenticity of the package according to instructionsInstall the downloaded package(s) with the command:# yum localinstall *.rpmWhen the list of updated packages is displayed, agree to apply the updates by pressingY on the keyboard. Wait for the updates to finish installing and make sure there are no errors during the installation.

Date of last modification: 08.09.2021