WordPress Paid Memberships Pro plugin before 2.6.7 is susceptible to blind SQL injection. The plugin does not escape the discount_code in one of its REST routes before using it in a SQL statement. An attacker can possibly obtain sensitive information, modify data, and/or execute unauthorized administrative operations in the context of the affected site.
View the template here CVE-2021-25114.yaml
References:
https://nvd.nist.gov/vuln/detail/CVE-2021-25114