Enforce GCP VPC Network Firewall Rules with Port Ranges to Block Incoming Traffic
Ensure that your Google Cloud VPC network firewall rules don't have range of ports configured to allow inbound traffic, in order to protect associated virtual machine instances against Denial-of-Service (DoS) attacks or brute-force attacks. To follow cloud security best practices, it is strongly recommended to open only specific ports within your firewall rules, based on your application requirements.
This policy pack can help you configure the following settings for Network firewalls:
- Revoke firewall rules that allow incoming traffic from all IP addresses
- Revoke firewall rules that have port range size of greater than 1
Getting Started
Requirements
- Terraform
- Guardrails mods:
Credentials
To create a policy pack through Terraform:
- Ensure you have
Turbot/Admin
permissions (or higher) in Guardrails - Create access keys in Guardrails
And then set your credentials:
export TURBOT_WORKSPACE=myworkspace.acme.comexport TURBOT_ACCESS_KEY=acce6ac5-access-key-hereexport TURBOT_SECRET_KEY=a8af61ec-secret-key-here
Please see Turbot Guardrails Provider authentication for additional authentication methods.
Usage
Install Policy Pack
NoteBy default, installed policy packs are not attached to any resources.
Policy packs must be attached to resources in order for their policy settings to take effect.
Clone:
git clone https://github.com/turbot/guardrails-samples.gitcd guardrails-samples/policy_packs/gcp/network/enforce_firewall_rules_with_port_ranges_to_not_allow_incoming_traffic
Run the Terraform to create the policy pack in your workspace:
terraform initterraform plan
Then apply the changes:
terraform apply
Apply Policy Pack
Log into your Guardrails workspace and attach the policy pack to a resource.
If this policy pack is attached to a Guardrails folder, its policies will be applied to all accounts and resources in that folder. The policy pack can also be attached to multiple resources.
For more information, please see Policy Packs.
Enable Enforcement
TipYou can also update the policy settings in this policy pack directly in the Guardrails console.
Please note your Terraform state file will then become out of sync and the policy settings should then only be managed in the console.
By default, the policies are set to Check
in the pack's policy settings. To enable automated enforcements, you can switch these policies settings by adding a comment to the Check
setting and removing the comment from one of the listed enforcement options:
resource "turbot_policy_setting" "gcp_network_firewall_ingress_rules_approved" { resource = turbot_policy_pack.main.id type = "tmod:@turbot/gcp-network#/policy/types/firewallIngressRulesApproved" # value = "Check: Approved" value = "Enforce: Delete unapproved"}
Then re-apply the changes:
terraform planterraform apply