The User Registration & Membership – Custom Registration Form Builder, Custom Login Form, User Profile, Content Restriction & Membership Plugin plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 4.4.8. This is due to missing or incorrect nonce validation on the 'process_row_actions' function with the 'delete' action. This makes it possible for unauthenticated attackers to delete arbitrary post via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.

The User Registration & Membership – Custom Registration Form Builder, Custom Login Form, User Profile, Content Restriction & Membership Plugin for WordPress is vulnerable to Stored Cross-Site Scripting via multiple shortcode attributes in all versions up to, and including, 4.4.6 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

The User Registration & Membership plugin for WordPress is vulnerable to SQL Injection via the 's' parameter in version 4.3.0. This is due to insufficient escaping on the user supplied parameter and lack of sufficient preparation on the existing SQL query. This makes it possible for authenticated attackers, with administrator-level access and above, to append additional SQL queries into already existing queries that can be used to extract sensitive information from the database.

The User Registration plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's urcr_restrict shortcode in all versions up to, and including, 4.2.4 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.