Magento 2.1.x Notice: Magento 2.1.18 is the final 2.1.x release. After June 2019, Magento 2.1.x will no longer receive security patches, quality fixes, or documentation updates. To maintain your site's performance, security, and PCIPayment Card Industry: Refers to debit and credit cards and their associated businesses. compliance, upgrade to the latest version of Magento. The Magento User Guide 2.1.x remains available in PDF for Open Source and Commerce.
In this section of the guide, you will learn security best practices, how to manage AdminThe password-protected back office of your store where orders, catalog, content, and configurations are managed. sessions and credentials, implement CAPTCHA, and manage website restrictions.
Stop by the Security Center and sign up for the Security Alert Registry to receive the latest information on potential vulnerabilities and best practices.