The Sophos Web Appliance Remote / Secure Web Gateway server (version 4.2.1.3) is vulnerable to a Remote Command Injection vulnerability in its web administrative interface. These vulnerabilities occur in MgrDiagnosticTools.php (/controllers/MgrDiagnosticTools.php), in the component responsible for performing diagnostic tests with the UNIX wget utility. The application doesn\'t properly escape the information passed in the \'url\' variable before calling the executeCommand class function ($this->dtObj->executeCommand). This function calls exec() with unsanitized user input allowing for remote command injection. The page that contains the vulnerabilities, /controllers/MgrDiagnosticTools.php, is accessed by a built-in command answered by the administrative interface. The command that calls to that vulnerable page (passed in the \'section\' parameter) is: \'configuration\'. Exploitation of this vulnerability yields shell access to the remote machine under the \'spiderman\' user account.