The Simple Membership WP user Import plugin for WordPress is vulnerable to SQL Injection via the ‘orderby’ parameter in versions up to, and including, 1.7 due to insufficient escaping on the user supplied parameter. This makes it possible for authenticated attackers with administrative privileges to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The Simple Membership WordPress plugin before 4.1.3 allows user to change their membership at the registration stage due to insufficient checking of a user supplied parameter.

The Simple Membership WordPress plugin before 4.1.3 does not properly validate the membership_level parameter when editing a profile, allowing members to escalate to a higher membership level by using a crafted POST request.

The Simple Membership WordPress plugin before 4.1.1 does not properly sanitise and escape parameters before outputting them back in AJAX actions, leading to Reflected Cross-Site Scripting

The Simple Membership WordPress plugin before 4.1.0 does not have CSRF check in place when deleting Transactions, which could allow attackers to make a logged in admin delete arbitrary transactions via a CSRF attack

The Simple Membership WordPress plugin before 4.0.9 does not have CSRF check when deleting members in bulk, which could allow attackers to make a logged in admin delete them via a CSRF attack

SQL injection vulnerability in Sourcecodester Simple Membership System v1 by oretnom23, allows attackers to execute arbitrary SQL commands via the username and password parameters.

The simple-membership plugin before 3.3.3 for WordPress has multiple CSRF issues.

The simple-membership plugin before 3.5.7 for WordPress has XSS.

The Simple Membership plugin before 3.8.5 for WordPress has CSRF affecting the Bulk Operation section.