Amazon Linux 2023 must define default permissions for all authenticated users in such a way that the user can only read and modify their own files.

Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access.

Satisfies: SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00230

Verify Amazon Linux 2023 defines default permissions for all authenticated users in such a way that the user can only read and modify their own files with the following command:

Note: If the value of the "UMASK" parameter is set to "000" in "/etc/login.defs" file, the Severity is raised to a CAT I.

# grep -i umask /etc/login.defs UMASK 077

If the value for the "UMASK" parameter is not "077", or the "UMASK" parameter is missing or is commented out, this is a finding.

Configure Amazon Linux 2023 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files.

Add or edit the lines for the "UMASK" parameter in the "/etc/login.defs" file to "077":

UMASK 077