Vulnerability Discussion

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

With a UMASK of 077, files will be created with 0600 permissions (owner read/write only) and directories will have 0700 permissions (owner read/write/execute only).

Check

Verify AlmaLinux OS 9 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 the "/etc/login.defs" file, the severity is raised to a CAT I.

$ grep 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.

Fix

Configure AlmaLinux OS 9 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