A path disclosure vulnerability 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. Requests for a specific file path could result in a redirect to the URL of the Magento admin panel, disclosing its location to potentially unauthorized parties.
https://magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-33