This indicates an attack attempt against a SQL Injection vulnerability in WordPress Video Player.
The vulnerability is a result of the application's failure to properly sanitize user input before using it in a SQL query. As a result, a remote attacker can send a crafted query to execute SQL commands on a vulnerable server.
WordPress Video Player before 1.5.18
System Compromise: Remote attackers can add, view, delete or modify data in the database of the affected application
Upgrade WordPress Video Player to version 1.5.18 or later