This indicates an attack attempt to exploit a SQL Injection vulnerability in Joomla content management system.
The vulnerability is due to insufficient validation of HTTP parameters when processing HTTP requests. It may allow remote attackers to execute arbitrary SQL statements via a crafted HTTP request which could lead to arbitrary code execution with database privileges.
Joomla version 3.7.0
System Compromise: Remote attackers can add, view, delete or modify data in the database of the affected application
Apply the most recent upgrade or patch from the vendor.