Metadata

Id: d3f8e9c1-7a2b-4d5f-90e2-123456789abc

Cloud Provider: GCP

Platform: Terraform

Severity: Medium

Category: Networking and Firewall

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• Provider Reference

Description

Allowing ingress from 0.0.0.0/0 on port 21 (FTP) in a firewall rule (source_ranges = ["0.0.0.0/0"]) exposes the FTP service to the entire internet, significantly increasing the risk of unauthorized access and brute-force attacks. FTP traffic is often unencrypted, which could enable attackers to intercept credentials or exfiltrate sensitive data if unrestricted access is permitted. Restricting ingress to trusted IP ranges (for example, source_ranges = ["192.168.1.0/24"]) reduces the attack surface and helps maintain data security.

Compliant Code Examples

resource "google_compute_firewall" "good_example" {
  name    = "good-firewall"
  network = "default"

  allow {
    protocol = "tcp"
    ports    = ["21"]
  }

  source_ranges = ["192.168.1.0/24"] # Restricted ingress for FTP
}

Non-Compliant Code Examples

resource "google_compute_firewall" "bad_example" {
  name    = "bad-firewall"
  network = "default"

  allow {
    protocol = "tcp"
    ports    = ["21"]
  }

  source_ranges = ["0.0.0.0/0"] # Unrestricted ingress for FTP
}