A cryptograhic flaw 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. A weak cryptograhic mechanism is used to generate the intialization vector in multiple security relevant contexts.
github.com/FriendsOfPHP/security-advisories/blob/master/magento/product-community-edition/CVE-2019-7886.yaml
magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-33
nvd.nist.gov/vuln/detail/CVE-2019-7886
web.archive.org/web/20220121011306/https://magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-33