This indicates an attack attempt to exploit a SQL Injection vulnerability in Joomla.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application. A remote attacker can exploit this to send a crafted query to execute SQL commands on a vulnerable server leading to full admin access on vulnerable system.
Joomla 3.0 through 3.4.4
System Compromise: Remote attackers can gain control of vulnerable systems.
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