The `flow/admin/moniteur.php` script in Use It Flow administration website before 10.0.0 is vulnerable to Remote Code Execution. When handling GET requests, the script takes user-supplied input from the `action` URL parameter, performs insufficient validation, and incorporates this input into a string that is subsequently executed by the `eval()` function. Although a `method_exists()` check is performed, it only validates the part of the user input *before* the first parenthesis `(`, allowing an attacker to append arbitrary PHP code after a valid method call structure. Successful exploitation allows an unauthenticated or trivially authenticated attacker to execute arbitrary PHP code on the server with the privileges of the web server process.