An XPath entity injection vulnerability exists in Magento 2.2 prior to 2.2.10, Magento 2.3 prior to 2.3.3 or 2.3.2-p1. An attacker can craft a GET request to page cache block rendering module that gets passed to XML data processing engine without validation. The crafted key/value GET request data allows an attacker to limited access to underlying XML data.
As per the Magento Release 2.3.3, if you have already implemented the pre-release version of this patch (2.3.2-p1), it is highly recommended to promptly upgrade to 2.3.2-p2.
github.com/FriendsOfPHP/security-advisories/blob/master/magento/product-community-edition/CVE-2019-8158.yaml
github.com/magento/magento2
magento.com/security/patches/magento-2.3.3-and-2.2.10-security-update
nvd.nist.gov/vuln/detail/CVE-2019-8158
web.archive.org/web/20220121051105/https://magento.com/security/patches/magento-2.3.3-and-2.2.10-security-update