FreeScout is a self-hosted help desk and shared mailbox. Versions prior to 1.8.128 are vulnerable to OS Command injection in the tools.php source file. The value of the php path parameter is being execut as an OS command by the shell exec function, without validating it. This allows an adversary to execute malicious OS commands on the server. A practical demonstration of the successful command injection attack extracted the passwd file of the server. This represented the complete compromise of the server hosting the FreeScout application. This attack requires an attacker to know the App Key of the application. This limitation makes the Attack Complexity to be High. If an attacker gets hold of the App Key, the attacker can compromise the Complete server on which the application is deployed. Version 1.8.128 contains a patch for this issue.