linux-formula/metadata/service/system/cis/cis-5-4-4.yml

# CIS 5.4.4 Ensure default user umask is 027 or more restrictive (Scored)
#
# Description
# ===========
# The default umask determines the permissions of files created by users.
# The user creating the file has the discretion of making their files and
# directories readable by others via the chmod command. Users who wish to
# allow their files and directories to be readable by others by default may
# choose a different default umask by inserting the umask command into the
# standard shell configuration files ( .profile , .bashrc , etc.) in their
# home directories.
#
# Rationale
# =========
# Setting a very secure default value for umask ensures that users make a
# conscious choice about their file permissions. A default umask setting of
# 077 causes files and directories created by users to not be readable by
# any other user on the system. A umask of 027 would make files and
# directories readable by users in the same Unix group, while a umask of 022
# would make files readable by every user on the system.
#
# Audit
# =====
# Run the following commands and verify all umask lines returned are 027 or
# more restrictive.
#
#   # grep "^umask" /etc/bash.bashrc
#   umask 027
#   # grep "^umask" /etc/profile
#   umask 027
#
# Remediation
# ===========
# Edit the /etc/bash.bashrc and /etc/profile files (and the appropriate files
# for any other shell supported on your system) and add or edit any umask
# parameters as follows:
#
#   umask 027
#
# Notes
# =====
# The audit and remediation in this recommendation apply to bash and shell.
# If other shells are supported on the system, it is recommended that their
# configuration files also are checked.
#
# Other methods of setting a default user umask exist however the shell
# configuration files are the last run and will override other settings if
# they exist therefore our recommendation is to configure in the shell
# configuration files. If other methods are in use in your environment they
# should be audited and the shell configs should be verified to not override.
#
parameters:
  linux:
    system:
      shell:
        umask: "027"