The Red Hat Enterprise Linux operating system must be configured so that the PAM system service is configured to store only encrypted representations of passwords.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-204415	RHEL-07-010200	SV-204415r603261_rule		Medium

Description
Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text.

STIG	Date
Red Hat Enterprise Linux 7 Security Technical Implementation Guide	2020-12-08

Details

Check Text ( C-4539r88437_chk )
Verify the PAM system service is configured to store only encrypted representations of passwords. The strength of encryption that must be used to hash passwords for all accounts is SHA512. Check that the system is configured to create SHA512 hashed passwords with the following command: # grep password /etc/pam.d/system-auth /etc/pam.d/password-auth Outcome should look like following: /etc/pam.d/system-auth-ac:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok /etc/pam.d/password-auth:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok If the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" configuration files allow for password hashes other than SHA512 to be used, this is a finding.

Check Text ( C-4539r88437_chk )

Verify the PAM system service is configured to store only encrypted representations of passwords. The strength of encryption that must be used to hash passwords for all accounts is SHA512.

Check that the system is configured to create SHA512 hashed passwords with the following command:

# grep password /etc/pam.d/system-auth /etc/pam.d/password-auth

Outcome should look like following:
/etc/pam.d/system-auth-ac:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok
/etc/pam.d/password-auth:password sufficient pam_unix.so sha512 shadow try_first_pass use_authtok

If the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" configuration files allow for password hashes other than SHA512 to be used, this is a finding.

Fix Text (F-4539r88438_fix)
Configure the operating system to store only SHA512 encrypted representations of passwords. Add the following line in "/etc/pam.d/system-auth": pam_unix.so sha512 shadow try_first_pass use_authtok Add the following line in "/etc/pam.d/password-auth": pam_unix.so sha512 shadow try_first_pass use_authtok Note: Manual changes to the listed files may be overwritten by the "authconfig" program. The "authconfig" program should not be used to update the configurations listed in this requirement.

Fix Text (F-4539r88438_fix)

Configure the operating system to store only SHA512 encrypted representations of passwords.

Add the following line in "/etc/pam.d/system-auth":
pam_unix.so sha512 shadow try_first_pass use_authtok

Add the following line in "/etc/pam.d/password-auth":
pam_unix.so sha512 shadow try_first_pass use_authtok

Note: Manual changes to the listed files may be overwritten by the "authconfig" program. The "authconfig" program should not be used to update the configurations listed in this requirement.