The Mainframe Product must require the change of at least eight of the total number of characters when passwords are changed.

If the application allows the user to consecutively reuse extensive portions of passwords, this increases the chances of password compromise by increasing the window of opportunity for attempts at guessing and brute-force attacks.

The number of changed characters refers to the number of changes required with respect to the total number of positions in the current password. In other words, characters may be the same within the two passwords; however, the positions of the like characters must be different.

If the Mainframe Product employs an external security manager (ESM) for all account management functions, this is not applicable.

Examine user account management configurations.

If the Mainframe Product account management settings do not require the change of at least eight of the total characters when passwords are changed, this is a finding.

Configure the Mainframe Product account management settings to require the change of at least 8 of the total characters when passwords are changed.