# CIS 4.4 — Implement and Manage a Firewall on Servers

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_cis_44_2d9f489122-cis-44-implement-and-manage-a-firewall-on-servers
- Section: [Solutions](https://support.icompaas.com/support/solutions) › [AWS Checks New Version](https://support.icompaas.com/support/solutions/62000112673) › [Protect](https://support.icompaas.com/support/solutions/folders/f_gen_62000112673_protect)
- Last updated: 2026-05-30
- Publisher: iCompaas, Inc. (https://www.icompaas.com)

CIS · Control 4.4 · Priority: critical · Component: Protect

### What this control covers

Implement and manage a firewall on servers, where supported. Example implementations include a virtual firewall, operating system firewall, or a third-party firewall agent.

### Why it matters

A defended network limits blast radius after an initial compromise — the difference between an incident and a breach is often the controls described here.

### How to implement

#### AWS

Segment workloads into separate **VPCs/accounts per environment**. Use **security groups** as stateful allow-lists (least-port, source by SG ID not 0.0.0.0/0) and **VPC Flow Logs** to CloudWatch/S3. Front public services with **AWS WAF + Shield Advanced** and use **PrivateLink/VPC Endpoints** to keep service traffic off the internet.

#### Azure

Use **Network Security Groups** and **Application Security Groups** for east-west, and an **Azure Firewall** or NVA in a hub VNet for north-south. Enforce **Private Endpoints** for PaaS and turn on **Defender for Cloud — Network** for adaptive hardening recommendations.

#### GCP

Use **VPC Service Controls** to draw a perimeter around sensitive APIs and a hierarchical **Firewall policy** at the org/folder level so projects inherit a deny-by-default posture. Front HTTP workloads with the global **Cloud Load Balancer + Cloud Armor**.

### Evidence to collect

-   `infra_scan` — See the iCompaas Evidence library for the canonical source for this evidence type.
-   `vendor_risk_management` — See the iCompaas Evidence library for the canonical source for this evidence type.

Infrastructure posture tooling (AWS Config, Azure Policy, Nessus) verifies platform hardening. Third-party risk management evidence (assessments, contracts, due diligence) shows supplier oversight. Focus: Implement and Manage a Firewall on Servers.

### Quick checklist

-   Implement And Manage — Network / Servers
-   Protect — Network / Servers

### Related articles on this site

-   [Microsoft Cloud Security Posture Management (CSPM)](https://support.icompaas.com/support/solutions/articles/62000234105-microsoft-cloud-security-posture-management-cspm-)
-   [4.12 Ensure the Latest Operating System Updates Are Installed On Your Virtual Machines in All Projects (Manual)](https://support.icompaas.com/support/solutions/articles/62000233026-4-12-ensure-the-latest-operating-system-updates-are-installed-on-your-virtual-machines-in-all-project)
-   [Ensure Image Vulnerability Scanning using Microsoft Defender for Cloud (MDC) image scanning or a third-party provider](https://support.icompaas.com/support/solutions/articles/62000234646-ensure-image-vulnerability-scanning-using-microsoft-defender-for-cloud-mdc-image-scanning-or-a-thir)
-   [2.10 Ensure that Microsoft Cloud App Security (MCAS) integration with Security Center is selected](https://support.icompaas.com/support/solutions/articles/62000219760-2-10-ensure-that-microsoft-cloud-app-security-mcas-integration-with-security-center-is-selected)

## Related compliance guidance

- [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Configuration checks like this one are the technical half of a SOC 2 / ISO 27001 programme — the guide shows where they fit, what else an auditor expects, and how to evidence them.
- [ISO/IEC 27001:2022 compliance: a practical implementation guide](https://support.icompaas.com/compliance/iso-27001-2022): ISO 27001 Annex A.8 (technological controls) is where cloud hardening evidence lands; the guide shows how to run the ISMS around it.