This indicates an attack attempt to exploit a Command Injection Vulnerability in YouPHPTube.
A remote attacker with knowledge of the database credentials could exploit this vulnerability by sending a crafted request to checkConfiguration.php and then subsequently browsing to the homepage. Successful exploitation could result in arbitrary code execution on the target system under the context of the server process.
YouPHPTube YouPHPTube 7.4
System Compromise: Remote attackers can gain control of vulnerable systems.
Apply the most recent upgrade or patch from the vendor.