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.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-274145 | AZLX-23-002410 | SV-274145r1120423_rule | CCI-000366 | medium |
| Description | ||||
| 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 | ||||
| STIG | Date | |||
| Amazon Linux 2023 Security Technical Implementation Guide | 2026-02-27 | |||
Details
Check Text (C-274145r1120423_chk)
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.
Fix Text (F-78141r1120422_fix)
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