SSH Access Is Not Restricted

• Query id: c4dcdcdf-10dd-4bf4-b4a0-8f6239e6aaa0
• Query name: SSH Access Is Not Restricted
• Platform: Terraform
• Severity: Medium
• Category: Networking and Firewall
• URL: Github

Description

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

Code samples

Code samples with security vulnerabilities

Positive test num. 1 - tf file

resource "google_compute_firewall" "positive1" {
  name    = "test-firewall"
  network = google_compute_network.default.name
  direction = "INGRESS"
  source_ranges = ["0.0.0.0/0"]

  allow {
    protocol = "icmp"
  }

  allow {
    protocol = "tcp"
    ports    = ["22", "80", "3389", "8080", "1000-2000"]
  }

  source_tags = ["web"]
}

resource "google_compute_firewall" "positive2" {
  name    = "test-firewall"
  network = google_compute_network.default.name

  source_ranges = ["0.0.0.0/0"]

  allow {
    protocol = "icmp"
  }

  allow {
    protocol = "tcp"
    ports    = ["80", "8080", "1000-2000","21-3390"]
  }

  source_tags = ["web"]
}

resource "google_compute_firewall" "positive3" {
  name    = "test-firewall"
  network = google_compute_network.default.name

  source_ranges = ["0.0.0.0/0"]

  allow {
    protocol = "icmp"
  }

  allow {
    protocol = "all"
  }

  source_tags = ["web"]
}

Code samples without security vulnerabilities

Negative test num. 1 - tf file

resource "google_compute_firewall" "negative1" {
  name    = "test-firewall"
  network = google_compute_network.default.name

  allow {
    protocol = "icmp"
  }

  allow {
    protocol = "tcp"
    ports    = ["80", "8080", "1000-2000"]
  }

  source_tags = ["web"]
}