Ensure the Default C Shell Umask is Set Correctly

An XCCDF Rule

Description

To ensure the default umask for users of the C shell is set properly, add or correct the umask setting in /etc/csh.cshrc to read as follows:

umask

Rationale

The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.

ID: xccdf_org.ssgproject.content_rule_accounts_umask_etc_csh_cshrc
Severity: Medium
References: 18

APO13.01 BAI03.01 BAI03.02 BAI03.03

CCI-000366

4.3.4.3.3

A.14.1.1 A.14.2.1 A.14.2.5 A.6.1.5

CIP-003-8 R5.1.1 CIP-003-8 R5.3 CIP-004-6 R2.3 CIP-007-3 R2.1 CIP-007-3 R2.2 CIP-007-3 R2.3 CIP-007-3 R5.1 CIP-007-3 R5.1.1 CIP-007-3 R5.1.2

AC-6(1) CM-6(a)

PR.IP-2

SRG-OS-000480-GPOS-00227 SRG-OS-000480-GPOS-00228

CCE-80203-3
Updated: about 1 year ago

- name: XCCDF Value var_accounts_user_umask # promote to variable
  set_fact:
    var_accounts_user_umask: !!str <xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_accounts_user_umask" use="legacy"/>
  tags:
    - always
- name: Check if umask in /etc/csh.cshrc is already set
  ansible.builtin.lineinfile:
    path: /etc/csh.cshrc
    regexp: ^(\s*)umask\s+.*
    state: absent
  check_mode: true
  changed_when: false
  register: umask_replace
  tags:
  - CCE-80203-3
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_csh_cshrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Replace user umask in /etc/csh.cshrc
  ansible.builtin.replace:
    path: /etc/csh.cshrc
    regexp: ^(\s*)umask(\s+).*
    replace: \g<1>umask\g<2>{{ var_accounts_user_umask }}
  when: umask_replace.found > 0
  tags:
  - CCE-80203-3
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_csh_cshrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Ensure the Default umask is Appended Correctly
  ansible.builtin.lineinfile:
    create: true
    path: /etc/csh.cshrc
    line: umask {{ var_accounts_user_umask }}
  when: umask_replace.found == 0
  tags:
  - CCE-80203-3
  - NIST-800-53-AC-6(1)
  - NIST-800-53-CM-6(a)
  - accounts_umask_etc_csh_cshrc
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy


var_accounts_user_umask='<xccdf-1.2:sub xmlns:xccdf-1.2="http://checklists.nist.gov/xccdf/1.2" idref="xccdf_org.ssgproject.content_value_var_accounts_user_umask" use="legacy"/>'


grep -q "^\s*umask" /etc/csh.cshrc && \
  sed -i -E -e "s/^(\s*umask).*/\1 $var_accounts_user_umask/g" /etc/csh.cshrcif ! [ $? -eq 0 ]; then
    echo "umask $var_accounts_user_umask" >> /etc/csh.cshrc
fi

Ensure the Default C Shell Umask is Set Correctly

Description

Rationale

Remediation - Ansible

Remediation - Shell Script