Google Compute network using firewall rule that allows all ports

Docs > Datadog Security > Code Security > Infrastructure as Code (IaC) Security > IaC Security Rules > Google Compute network using firewall rule that allows all ports

Metadata

Id: 3602d273-3290-47b2-80fa-720162b1a8af

Cloud Provider: GCP

Platform: Ansible

Severity: Medium

Category: Networking and Firewall

Learn More

Provider Reference

Description

Allowing ingress on all ports (0-65535) greatly increases attack surface by exposing every service port to network scanning and exploitation. This can lead to unauthorized access, lateral movement, and easier compromise of instances.

This rule flags Ansible tasks using the google.cloud.gcp_compute_firewall or gcp_compute_firewall module where the rule is ingress and the allowed entry contains ports: ["0-65535"] for a firewall associated with a compute network referenced by a preceding google.cloud.gcp_compute_network/gcp_compute_network task.

The allowed.ports property must not include "0-65535". Instead, specify explicit ports or narrow ranges (for example "80", "443", or "1024-2048") and restrict access with appropriate sourceRanges or other selectors.

Secure example (allow only HTTP/HTTPS from a limited source range):

- name: Allow HTTP and HTTPS from internal range
  google.cloud.gcp_compute_firewall:
    name: allow-web
    network: "{{ my_network }}"
    direction: INGRESS
    allowed:
      - IPProtocol: tcp
        ports: ["80", "443"]
    sourceRanges: ["10.0.0.0/8"]

Compliant Code Examples

- name: create a firewall
  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
    network: "{{ my_network }}"
- name: create a network
  google.cloud.gcp_compute_network:
    name: test_object
    auto_create_subnetworks: 'true'
    project: test_project
    auth_kind: serviceaccount
    service_account_file: "/tmp/auth.pem"
    state: present
  register: my_network

Non-Compliant Code Examples

- name: create a firewall2
  google.cloud.gcp_compute_firewall:
    name: test_object
    allowed:
    - ip_protocol: tcp
      ports:
      - '0-65535'
    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
    network: "{{ my_network2 }}"
- name: create a network2
  google.cloud.gcp_compute_network:
    name: test_object
    auto_create_subnetworks: 'true'
    project: test_project
    auth_kind: serviceaccount
    service_account_file: "/tmp/auth.pem"
    state: present
  register: my_network2