# CIS Controls v8 4.5 — Implement and Manage a Firewall on End-User Devices - Source: https://support.icompaas.com/compliance/cis-controls-v8/4-5-implement-and-manage-a-firewall-on-end-user-devices - Section: [Compliance](https://support.icompaas.com/compliance) › [CIS Critical Security Controls v8](https://support.icompaas.com/compliance/cis-controls-v8) › Control 4 — Secure Configuration of Enterprise Assets and Software - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **CIS Controls v8**·Control `4.5`·critical·Component: **Protect** ## What this control requires > 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. > > — CIS Controls v8, Control 4.5 ### In plain English 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. In practice, this means you can prove you implement and manage end user-level controls on a defined cadence. ## Why it matters The CIS Controls are an industry-vetted, prioritised defence: skipping a safeguard widens the attack surface that the safeguards above and below it assume is closed. Audit frameworks (FedRAMP, PCI DSS, HIPAA) all cite CIS as evidence of due care. This control is rated **critical** in the source catalogue. Treat gaps here as production incidents in the risk register, not housekeeping. ## What an auditor looks for A CIS-aligned reviewer wants to see (a) which Implementation Group you are targeting, (b) a documented owner for the safeguard, and (c) a tooling or process artefact (config, scan output, ticket) that proves the safeguard runs on the cadence the control demands. Within **Protect**, the assessor will trace your implementation back to the catalogue reference (Control 4.5) and look for objective evidence on the latest two assessment cycles. ## How to implement #### Cloud Posture **CSPM.** Run Wiz / Prisma / Defender for Cloud / Security Command Center over every account; auto-ticket findings above your accepted-risk threshold. #### Configuration Management **Policy-as-code.** Codify the control as Service Control Policies (AWS), Azure Policy initiatives, or Organisation Policy (GCP) so the platform enforces what the document promises. **IaC.** Gate Terraform / Pulumi / CloudFormation changes with Checkov / tfsec / OPA so misconfigurations never reach production. **Drift.** Run a CSPM (Wiz / Prisma / Defender for Cloud / Security Command Center) over every account and route findings to a single risk register. #### Network Security **AWS.** VPC Flow Logs to S3, default-deny security groups, AWS Network Firewall for north-south, and Transit Gateway for hub-and-spoke segmentation. **Azure.** NSGs with deny-by-default, Azure Firewall Premium with TLS inspection, Private Endpoints for PaaS, and Microsoft Defender for Cloud's secure score for drift. **GCP.** VPC Service Controls perimeters around sensitive APIs, Cloud NGFW Enterprise for L7 inspection, Private Service Connect for managed services. ### Operational checklist - **Implement And Manage.** Document the trigger, the owner and the cadence. - **Protect.** Document the trigger, the owner and the cadence. - **Scope:** end user, network. ## Evidence to collect - **Infra Scan.** Continuous infrastructure-posture telemetry — AWS Config, Azure Policy compliance, GCP Organisation Policy, Wiz / Prisma findings. Infrastructure posture tooling (AWS Config, Azure Policy, Nessus) verifies platform hardening. Focus: Implement and Manage a Firewall on End-User Devices. ## Common pitfalls - Treating CSPM findings as a backlog instead of a hot queue: findings older than the policy SLA accumulate until the auditor asks why. - Manual cloud-console changes that never make it back to Terraform — drift accumulates until the next outage forces a reconciliation. - Default-allow egress rules; East-West traffic with no segmentation; jump hosts on the public internet with password auth. ## How it maps to other frameworks Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit. - [**NIST SP 800-171 Rev. 3 3.13.6** — Network Communications - Deny by Default - Allow by Exception](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-13-6-network-communications-deny-by-default-allow-by-exception) - [**BSI C5:2020 COS-07** — Documentation of the network topology](https://support.icompaas.com/compliance/bsi-c5-2020/cos-07-documentation-of-the-network-topology) - [**ISO/IEC 27001:2022 A.8.21** — Security of network services](https://support.icompaas.com/compliance/iso-27001-2022/a-8-21-security-of-network-services) ## Related controls in CIS Controls v8 - [**Control 13.4** — Perform Traffic Filtering Between Network Segments](https://support.icompaas.com/compliance/cis-controls-v8/13-4-perform-traffic-filtering-between-network-segments) - [**Control 14.5** — Train Workforce Members on Causes of Unintentional Data Exposure](https://support.icompaas.com/compliance/cis-controls-v8/14-5-train-workforce-members-on-causes-of-unintentional-data-exposure) - [**Control 12.6** — Use of Secure Network Management and Communication Protocols](https://support.icompaas.com/compliance/cis-controls-v8/12-6-use-of-secure-network-management-and-communication-protocols) - [**Control 12.8** — Establish and Maintain Dedicated Computing Resources for All Administrative Work](https://support.icompaas.com/compliance/cis-controls-v8/12-8-establish-and-maintain-dedicated-computing-resources-for-all-administrative-work) - [**Control 4.9** — Configure Trusted DNS Servers on Enterprise Assets](https://support.icompaas.com/compliance/cis-controls-v8/4-9-configure-trusted-dns-servers-on-enterprise-assets) - [**Control 4.3** — Configure Automatic Session Locking on Enterprise Assets](https://support.icompaas.com/compliance/cis-controls-v8/4-3-configure-automatic-session-locking-on-enterprise-assets) ## References - [Center for Internet Security — CIS Controls v8](https://www.cisecurity.org/controls/v8) - Catalogue identifier: `Control 4.5` Topics: network securitycloud postureconfiguration managementfirewall management ## 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.