Improper Input Validation
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.
CWE-20 - Improper Input Validation
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.