Google Firewall should not allow SSH access (port 22) from the Internet (public CIDR block)

gcp_ssh_access_is_not_restricted

Severity

low

Vendor

GCP

Resource

AIM

Description

Google Firewall should not allow SSH access (port 22) from the Internet (public CIDR block) to ensure the principle of least privileges.

To fix it, you must avoid to allow port 22 with a source_ranges property using unrestricted range (0.0.0.0/0).

Learn more about this topic at Create a VPC-native cluster.

Examples

---
- name: ssh_unrestricted
  google.cloud.gcp_compute_firewall:
    name: test_object
    allowed:
    - ip_protocol: tcp
      ports:
      - '22'
    target_tags:
    - test-ssh-server
    - staging-ssh-server
    source_tags:
    - test-ssh-clients
    project: test_project
    auth_kind: serviceaccount
    service_account_file: "/tmp/auth.pem"
    state: present
    source_ranges:
    - "0.0.0.0/0"

Mitigation / Fix

---
- name: ssh_restricted
  google.cloud.gcp_compute_firewall:
    name: test_object
    denied:
    - ip_protocol: tcp
      ports:
      - '22'
    target_tags:
    - test-ssh-server
    - staging-ssh-server
    source_tags:
    - test-ssh-clients
    project: test_project
    auth_kind: serviceaccount
    service_account_file: /tmp/auth.pem
    state: present
    source_ranges:
    - 0.0.0.0