The Photon operating system must require the change of at least eight characters when passwords are changed.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-258817	SRG-OS-000072-GPOS-00040	PHTN-40-000038	SV-258817r1003632_rule	2024-07-11	2

Description
If the operating system 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 password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters.

Description

If the operating system 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 password length is an odd number then number of changed characters must be rounded up. For example, a password length of 15 characters must require the change of at least eight characters.

ℹ️ Check
At the command line, run the following command to verify at least eight different characters be used: # grep '^password.*pam_pwquality.so' /etc/pam.d/system-password Example result: password requisite pam_pwquality.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=15 difok=8 enforce_for_root dictcheck=1 If the "difok" option is not >= 8, is missing or commented out, this is a finding.

✔️ Fix
Navigate to and open: /etc/pam.d/system-password Configure the pam_pwquality.so line to have the "difok" option set to "8" as follows: password requisite pam_pwquality.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=15 difok=8 enforce_for_root dictcheck=1 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 Configure the pam_pwquality.so line to have the "difok" option set to "8" as follows: password requisite pam_pwquality.so dcredit=-1 ucredit=-1 lcredit=-1 ocredit=-1 minlen=15 difok=8 enforce_for_root dictcheck=1 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.