The Advanced Page Visit Counter plugin for WordPress is vulnerable to a type of attack called SQL Injection. This type of attack can happen when users are allowed to input data like names, email addresses, or other information. In this case, the Advanced Page Visit Counter plugin is vulnerable to this type of attack because it does not properly escape the data that is input by users and does not prepare the existing SQL query enough. If an attacker with user access privileges at least as high as a contributor is able to get access to the data, they could use additional SQL queries to extract sensitive information from the database.