The Photon operating system must require that new passwords are at least four characters different from the old password.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-256501	SRG-OS-000072-GPOS-00040	PHTN-30-000024	SV-256501r982198_rule	2024-12-16	1

Description
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks.

ℹ️ Check
At the command line, run the following command: # grep pam_cracklib /etc/pam.d/system-password\|grep --color=always "difok=." Expected result: password requisite pam_cracklib.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=8 minclass=4 difok=4 retry=3 maxsequence=0 enforce_for_root If the output does not include difok >= 4, this is a finding.

✔️ Fix
Navigate to and open: /etc/pam.d/system-password Add the following, replacing any existing "pam_cracklib.so" line: password requisite pam_cracklib.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=8 minclass=4 difok=4 retry=3 maxsequence=0 enforce_for_root Note: On vCenter appliances, the equivalent file must be edited under "/etc/applmgmt/appliance", if one exists, for the changes to persist after a reboot.

✔️ Fix

Navigate to and open: /etc/pam.d/system-password Add the following, replacing any existing "pam_cracklib.so" line: password requisite pam_cracklib.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=8 minclass=4 difok=4 retry=3 maxsequence=0 enforce_for_root Note: On vCenter appliances, the equivalent file must be edited under "/etc/applmgmt/appliance", if one exists, for the changes to persist after a reboot.