Information
The operating system must be configured so that /etc/pam.d/passwd implements /etc/pam.d/system-auth when changing passwords.
Pluggable authentication modules (PAM) allow for a modular approach to integrating authentication methods. PAM operates in a top-down processing model and if the modules are not listed in the correct order, an important security function could be bypassed if stack entries are not centralized.
Solution
Configure PAM to utilize /etc/pam.d/system-auth when changing passwords.
Add the following line to /etc/pam.d/passwd (or modify the line to have the required value):
Example: vim /etc/pam.d/passwd
Add, uncomment or update the following line:
password substack system-auth