To set the default umask to 0027

Purpose

To align with OS-hardening best practices, as defined by the Center for Information Security, or CIS, you can change the default login umask on a RHEL OS instance that hosts an NSP deployer host, NSP cluster node, or NSP component deployed outside the NSP cluster, to restrict file and directory access for non-root users.

Perform this procedure to set the default login umask on an NSP RHEL OS instance to 0027.

CAUTION 

CAUTION

Misconfiguration Risk

Performing the procedure on a RHEL OS that hosts NSP Release 22.11 or earlier software may have undesirable effects that include restricted system access.

You must perform the procedure only on a RHEL OS instance that hosts Release 23.4 or later NSP software.

Steps
 
1 

Log in as the root user on the station that hosts the OS.


2 

Open a console window.


3 

Back up the following files to a secure location on a station outside the management network for safekeeping:

  • /etc/bashrc

  • /etc/profile

  • /etc/login.defs


4 

Enter the following:

# sed -i 's/^\([[:space:]]*\)\(umask\|UMASK\)[[:space:]][[:space:]]*[0-9][0-9][0-9]/\1\2 027/' /etc/bashrc /etc/profile /etc/login.defs ↵


5 

Log out.


6 

Log in as the root user.


7 

Enter the following:

# umask ↵

The current umask value is displayed.


8 

Verify that the umask value is 0027.


9 

Close the console window.

End of steps