Disable snmpd Service

Description

The snmpd service can be disabled with the following command:

$ sudo systemctl mask --now snmpd.service

Rationale

Running SNMP software provides a network-based avenue of attack, and should be disabled if not needed.

Remediation

Ansible playbook

The following playbook can be run with Ansible to remediate the issue.

- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_snmpd_disabled

- name: Disable snmpd Service - Collect systemd Services Present in the System
  ansible.builtin.command: systemctl -q list-unit-files --type service
  register: service_exists
  changed_when: false
  failed_when: service_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "net-snmp" in ansible_facts.packages )
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_snmpd_disabled

- name: Disable snmpd Service - Ensure snmpd.service is Masked
  ansible.builtin.systemd:
    name: snmpd.service
    state: stopped
    enabled: false
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "net-snmp" in ansible_facts.packages )
  - service_exists.stdout_lines is search("snmpd.service", multiline=True)
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_snmpd_disabled

- name: Unit Socket Exists - snmpd.socket
  ansible.builtin.command: systemctl -q list-unit-files snmpd.socket
  register: socket_file_exists
  changed_when: false
  failed_when: socket_file_exists.rc not in [0, 1]
  check_mode: false
  when: ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman",
    "container"] and "net-snmp" in ansible_facts.packages )
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_snmpd_disabled

- name: Disable snmpd Service - Disable Socket snmpd
  ansible.builtin.systemd:
    name: snmpd.socket
    enabled: false
    state: stopped
    masked: true
  when:
  - ( ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
    and "net-snmp" in ansible_facts.packages )
  - socket_file_exists.stdout_lines is search("snmpd.socket", multiline=True)
  tags:
  - disable_strategy
  - low_complexity
  - low_disruption
  - low_severity
  - no_reboot_needed
  - service_snmpd_disabled