More Info:

This rule checks if AWS Network Firewall firewalls are deployed across multiple Availability Zones. The rule is NON_COMPLIANT if firewalls are deployed in only one Availability Zone or in fewer zones than the number listed in the optional parameter.

Risk Level

Low

Address

Availability

Compliance Standards

HIPAA,NIST,HITRUST,AWSWAF,SOC2,NISTCSF,PCIDSS

Triage and Remediation

Remediation

To remediate the misconfiguration of network firewalls deployed across multiple availability zones for AWS EC2 instances, follow these steps using the AWS Management Console:

  1. Access the AWS Management Console: Go to the AWS Management Console (https://aws.amazon.com/console/).

  2. Navigate to the VPC Dashboard:

    • Click on “Services” in the top menu bar.
    • Under the “Networking & Content Delivery” section, click on “VPC” to open the VPC Dashboard.
  3. Select the VPC with Misconfigured Network Firewalls:

    • In the VPC Dashboard, locate and select the VPC that contains the misconfigured network firewalls across multiple availability zones.
  4. Review the Network ACLs:

    • In the left-hand menu, click on “Network ACLs” to view the network access control lists associated with the selected VPC.
    • Review the existing network ACLs to identify any misconfigurations related to allowing or blocking traffic across availability zones.
  5. Edit the Network ACL Rules:

    • Select the network ACL that needs to be modified to enforce network firewall rules within the same availability zone.
    • Click on the “Inbound Rules” and “Outbound Rules” tabs to edit the rules as needed.
  6. Modify the Network ACL Rules:

    • Update the network ACL rules to ensure that the desired traffic is allowed or blocked within the same availability zone.
    • You may need to add specific rules to allow or deny traffic based on your organization’s security requirements.
  7. Save the Changes:

    • After making the necessary modifications to the network ACL rules, click on the “Save” or “Apply” button to apply the changes.
  8. Verify the Configuration:

    • Test the network connectivity between EC2 instances within the same availability zone to confirm that the network firewall rules are correctly configured.
  9. Monitor and Maintain:

    • Regularly monitor the network ACLs and security groups associated with your VPC to ensure ongoing compliance with your organization’s security policies.

By following these steps and updating the network ACL rules to enforce network firewalls within the same availability zone, you can remediate the misconfiguration of network firewalls deployed across multiple availability zones for AWS EC2 instances.