Magento 2.2 prior to 2.2.10, Magento 2.3 prior to 2.3.3 or 2.3.2-p1 uses cryptographically weak random number generator to brute-force the confirmation code for customer registration.
github.com/FriendsOfPHP/security-advisories/blob/master/magento/product-community-edition/CVE-2019-8113.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-2019-8113
web.archive.org/web/20220121051105/https://magento.com/security/patches/magento-2.3.3-and-2.2.10-security-update