Front-end identification
To start a program from the front-end platform, the front-end can open a terminal session on the application server. This is done for example by using a ssh, rlogin, or telnet terminal session. When the terminal session is open, the front-end sends some shell commands to set environment variables, like FGLSERVER, before starting the program to display the application forms on the front-end where the terminal session was initiated.
In this configuration, front-end identification takes place. The front-end identification prevents the display of application forms on a front-end that did not start the program on the server. If the front-end is not identified, a serious security issue can arise, as anyone could run a fake program to display on any front-end and ask for a password.
Front-end identification is achieved automatically by an initial protocol handshake. However, there can be a security hole if regular operating system users on the application server can overwrite the program or the shell script started by the front-end terminal session. Malicious programs can try to display the application on another workstation to read confidential data. As long as basic application users do not have read and write privileges on the program files, there is no risk. To make sure that program files on the server side are protected from basic users, create a special user on the server to manage the application program files, and give other users only read access to those files. As long as basic users cannot modify programs on the server side, there is no security issue.