Input validation vulnerability in Membership by Supsystic 1.5.0

The Membership by Supsystic plugin for WordPress is vulnerable to a security issue in versions up to, and including, 1.5.0. This issue can allow an authenticated attacker to access sensitive information from the database. The vulnerable code is caused by the lack of sufficient escaping of the user-supplied parameters, and the lack of preparation of the existing SQL query. This makes it possible for the attacker to add additional SQL queries to the existing query, which can lead to the sensitive information being exposed.