This indicates an attack attempt against an Security Bypass vulnerability in PHP Volunteer Management System.
The vulnerability is due to insufficient sanitizing of user supplied inputs in the application when handling HTTP requests. A remote attacker may be able to exploit this to execute arbitrary script code within the context of the application.
PHP Volunteer Management System v 1.0.2
Security Bypass: Remote attackers can bypass security checking of vulnerable systems.
System Compromise: Remote attackers can gain control of vulnerable systems.
Currently we are not aware of any officially supplied fix for this issue.