A denial-of-service (DoS) 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. By abusing insufficient brute-forcing defenses in the token exchange protocol, an unauthenticated attacker could disrupt transactions between the Magento merchant and PayPal.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-7928
• https://web.archive.org/web/20211206084839/https://magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-13
• https://github.com/FriendsOfPHP/security-advisories/blob/master/magento/product-community-edition/CVE-2019-7928.yaml
• https://magento.com/security/patches/magento-2.3.2-2.2.9-and-2.1.18-security-update-13