Information
The PASS_MIN_DAYS parameter in /etc/login.defs allows an administrator to prevent users from changing their password until a minimum number of days have passed since the last time the user changed their password. It is recommended that PASS_MIN_DAYS parameter be set to 7 or more days.
Rationale:
By restricting the frequency of password changes, an administrator can prevent users from repeatedly changing their password in an attempt to circumvent password reuse controls.
Solution
Set the PASS_MIN_DAYS parameter to 7 in /etc/login.defs :
PASS_MIN_DAYS 7
Modify user parameters for all users with a password set to match:
# chage --mindays 7 <user>
Additional Information:
You can also check this setting in /etc/shadow directly. The 4th field should be 7 or more for all users with a password.
Item Details
Category: CONFIGURATION MANAGEMENT, SYSTEM AND SERVICES ACQUISITION
References: 800-53|CM-2, 800-53|CM-6, 800-53|CM-7, 800-53|CM-7(1), 800-53|CM-9, 800-53|SA-3, 800-53|SA-8, 800-53|SA-10, CSCv6|16, CSCv7|4.4, CSCv7|16
Control ID: 6e275f3ce223450947cd9f0a1ee0b60b6234453af238f28b729472138b604c7b