Feature Article

The CHGPRF Command - Change My Own Profile - Really?

By Dan Riehl - SecureMyi.com

Did you know that your end users and IT staff members may be able to change their own User Profile settings?

Just like users can run the CHGPWD(Change Password) command to change their own password, there is another command CHGPRF(Change Profile) that may be used to change their own user profile.

Numerous User Profile attributes can be changed using this CHGPRF command. Certain attributes like Group Profile and Supplemental Group Profile cannot be changed. But that's little consolation when we find that our end users can change their initial program, initial menu, current library, job description, attention program, etc.

The CHGPRF command ships from IBM as *PUBLIC use, so it is available for general use. As you might suspect, the user must have at least *USE authority to the specified initial program, menu, job description, attention program, current library, etc. in order to make those kind of changes.

Certain parameters of the CHGPRF command are sensitive to the LMTCPB(Limit Capabilities) attribute of the user's profile. For instance, if the user is LMTCPB(*PARTIAL), they cannot change their initial program, current library or attention key handling program. They can however change their initial menu and all the other attributes. If the user is LMTCPB(*YES), they cannot change their initial program, initial menu, current library or attention key program, but they can change all the rest of their profile attributes like job description, user options, output queue, printer and even the textual description of their user profile.

You may be thinking that this is not really such a big deal since the only people on your system that can run this command are IT folks and a limited number of users that have access to the command line. Users that are defined as LMTCPB(*YES) cannot enter this command on a command line, and I doubt you would place this option on their menu. But, any user that has IBM i Access(Client Access) installed on their PC can use the RMTCMD command to run the CHGPRF command. It's as simple as going to a DOS prompt and running the command:

RMTCMD     CHGPRF   JOBD(QGPL/HIGHPRI)   TEXT('I am so cool')

The RMTCMD.exe on your PC does not pay any attention to the LMTCPB attribute of the user running the command. The user can run any command to which they are authorized. And, since RMTCMD is an integral part of IBM i Access for Windows, you cannot just remove it from all your PCs. It's best to write or buy an exit program for the remote command server that would control this type of activity.

My recommendation to you is to change the object authority of the CHGPRF command to make it *PUBLIC AUT(*EXCLUDE). To make that change, you can use either the EDTOBJAUT(Edit Object Authority) command or the GRTOBJAUT(Grant Object Authority) command.

And I really wonder, who came up with this CHGPRF command, which potentially allows users to skirt the settings set by the system administrator.