The Simple Membership MailChimp Integration WordPress plugin before 1.9.8 does not have CSRF checks in its settings page, allowing attackers to trick a logged-in administrator into changing the configured third-party API key. Once replaced, all subsequent member registration data (name, email, membership level) is sent to the attacker-controlled account.
The Simple Membership WordPress plugin before 4.7.7 does not verify that a PayPal payment notification was sent to the site's own configured merchant account before activating a membership, allowing unauthenticated users to activate or extend a membership using a payment made to an arbitrary PayPal account they control. This vulnerability affects WordPress sites using the Simple Membership plugin, particu [truncated]
The Simple Membership WordPress plugin before 4.7.8 does not verify whether user creation failed during registration before using the returned value as a user ID to update an account, allowing unauthenticated attackers to overwrite the primary administrator's account data (including the email address) and take over that account through the password reset flow.