A security bypass exists in Magento 2.1 prior to 2.1.18, Magento 2.2 prior to 2.2.9, Magento 2.3 prior to 2.3.2 that could be abused to execute arbitrary PHP code. An authenticated user can bypass security protections that prevent arbitrary PHP script upload via form data injection.
github.com/FriendsOfPHP/security-advisories/blob/master/magento/product-community-edition/CVE-2019-7871.yaml
github.com/magento/magento2
magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-13
nvd.nist.gov/vuln/detail/CVE-2019-7871
web.archive.org/web/20211206084839/https://magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-13