Title

Ubuntu 24.04 LTS default filesystem permissions must be defined in such a way that all authenticated users can read and modify only their own files. (Cat II impact)

Discussion

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

Check Content

Verify Ubuntu 24.04 LTS defines default permissions for all authenticated users in such a way that the user can read and modify only their own files with the following command: $ grep -i '^\s*umask' /etc/login.defs UMASK 077 If the "UMASK" variable is set to "000", this is a finding with the severity raised to a CAT I. If the value of "UMASK" is not set to "077", is commented out, or is missing, this is a finding.

Fix Text

Configure the system to define the default permissions for all authenticated users in such a way that the user can read and modify only their own files. Edit the "UMASK" parameter in the "/etc/login.defs" file to match the example below: UMASK 077

Additional Identifiers

Rule ID: SV-270716r1066637_rule

Vulnerability ID: V-270716

Group Title: SRG-OS-000480-GPOS-00228

Expert Comments

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