# CIS 4.5 — Implement and Manage a Firewall on End-User Devices

- Source: https://support.icompaas.com/support/solutions/articles/a_gen_cis_45_11bc3b2cec-cis-45-implement-and-manage-a-firewall-on-end-user-devices
- 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 4.5 · Priority: critical · Component: Protect

### What this control covers

Implement and manage a host-based firewall or port-filtering tool on end-user devices, with a default-deny rule that drops all traffic except those services and ports that are explicitly allowed.

### 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.

Infrastructure posture tooling (AWS Config, Azure Policy, Nessus) verifies platform hardening. Focus: Implement and Manage a Firewall on End-User Devices.

### Quick checklist

-   Implement And Manage — End User / Network
-   Protect — End User / Network

### Related articles on this site

-   [Ensure default network access rule for Storage Accounts is set to deny](https://support.icompaas.com/support/solutions/articles/62000219787-ensure-default-network-access-rule-for-storage-accounts-is-set-to-deny)
-   [NIST 800-171 3.13.6 Deny network communications traffic by default and allow network communications traffic by exception (i.e., deny all, permit by exception).](https://support.icompaas.com/support/solutions/articles/62000229261-nist-800-171-3-13-6-deny-network-communications-traffic-by-default-and-allow-network-communications-t)
-   [CMMC 2.0 SC.3.183 Deny network communications traffic by default and allow network communications traffic by exception (i.e., deny all, permit by exception).](https://support.icompaas.com/support/solutions/articles/62000229744-cmmc-2-0-sc-3-183-deny-network-communications-traffic-by-default-and-allow-network-communications-tra)
-   [Ensure Default Network Access Rule for Storage Accounts is Set to 'Deny' (Automated)](https://support.icompaas.com/support/solutions/articles/62000234013-ensure-default-network-access-rule-for-storage-accounts-is-set-to-deny-automated-)

## 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.