CIS Benchmarks: Infrastructure Hardening Guide

The Center for Internet Security (CIS) Benchmarks are the globally recognized standard for secure configuration of IT systems. Developed through a consensus-driven process involving cybersecurity experts worldwide, CIS Benchmarks provide prescriptive, platform-specific hardening guidelines for over 100 technologies including operating systems, cloud providers, databases, web servers, containers, and network devices. For security teams, CIS Benchmarks answer the most practical question in infrastructure security: exactly what settings should this system have?

What CIS Benchmarks Are and Who Issues Them

CIS is a nonprofit organization established in 2000 with a mission to make the connected world safer. The CIS Benchmarks program is its most widely adopted output — a library of technology-specific hardening guides developed through community consensus among hundreds of subject matter experts from government, industry, and academia.

Unlike frameworks that describe what to achieve at a high level, CIS Benchmarks are prescriptive. Each benchmark lists specific configuration settings, registry values, file permissions, and service states with exact recommended values. This specificity makes them directly implementable: a system administrator or infrastructure-as-code practitioner can apply CIS Benchmark recommendations without ambiguity about what "secure configuration" means in practice.

The benchmarks are continuously updated as technology platforms evolve. A benchmark for a specific Linux distribution, for example, may be updated several times per year as new features, patches, and vulnerabilities emerge. Organizations subscribing to CIS alerts receive notifications when benchmarks they rely on are updated.

Who Uses CIS Benchmarks

CIS Benchmarks are used by organizations of all sizes as the baseline for infrastructure security. They are referenced by numerous compliance frameworks — PCI DSS requires configuration standards, NIST CSF recommends secure configurations, and FedRAMP incorporates CIS Benchmark checks for system hardening. Auditors frequently reference CIS Benchmarks when evaluating configuration management controls during SOC 2 and ISO 27001 audits.

For cloud-native startups and SaaS companies, CIS cloud provider benchmarks (AWS Foundations, Azure Security Benchmark, GCP Foundations) provide a structured path to cloud security hardening that directly supports multiple compliance programs simultaneously. A single pass through AWS CIS Foundations simultaneously satisfies configuration management requirements for SOC 2, FedRAMP (if applicable), and NIST CSF — making CIS Benchmarks a highly leveraged investment.

Key Requirements: Profiles and Technology Categories

Each benchmark contains detailed configuration recommendations organized into two implementation profiles.

Level 1 profiles represent essential security settings that can be implemented with minimal impact on functionality. These are suitable for most organizations and cover the highest-value hardening actions: disabling unnecessary services, enforcing strong authentication, enabling audit logging, and applying baseline access restrictions. Level 1 is the appropriate starting point for virtually all organizations.

Level 2 profiles provide deeper hardening for environments requiring maximum security. They may disable functionality used by some legitimate workloads, making them more appropriate for sensitive or regulated environments than for general-purpose infrastructure. Level 2 is commonly required for high-impact FedRAMP systems and environments handling highly sensitive data.

The CIS Benchmark library spans the full infrastructure stack.

Operating Systems — Windows Server (multiple versions), Windows 10/11, Red Hat Enterprise Linux, Ubuntu, CentOS/AlmaLinux, macOS. Each OS benchmark covers user account settings, audit policy, network configuration, firewall rules, and service management.

Cloud Provider Configurations — AWS Foundations Benchmark, Microsoft Azure Security Benchmark, Google Cloud Platform Foundations Benchmark, and Oracle Cloud Infrastructure Benchmark. These are among the highest-value benchmarks for modern organizations, covering IAM configuration, logging and monitoring, networking, and storage security for each major cloud platform.

Containers and Kubernetes — Docker Benchmark, Kubernetes Benchmark, and managed Kubernetes service benchmarks (Amazon EKS, Azure AKS, Google GKE). Container environment hardening has become a critical security area as container adoption has grown.

Databases — Microsoft SQL Server, Oracle Database, PostgreSQL, MongoDB, MySQL. Database benchmarks cover authentication, access control, auditing, and encryption configuration.

Web Servers — Apache HTTP Server, Nginx, Microsoft IIS. These address server configuration, SSL/TLS settings, request handling, and access controls.

Network Devices — Cisco IOS, Palo Alto Networks, Juniper. Network device benchmarks address authentication, management plane access, routing security, and logging.

Implementation Approach

Start with the benchmarks most relevant to your environment. For cloud-native organizations, cloud provider benchmarks are the highest-priority starting point. For organizations with significant on-premises infrastructure, OS benchmarks for Windows and Linux deserve early attention.

Apply Level 1 profiles first. Use the CIS-CAT Pro scanning tool (or cloud-native equivalents) to assess your current compliance posture against each applicable benchmark. Generate a gap report identifying non-compliant settings. Prioritize remediations by potential impact — authentication and access control gaps typically carry the highest risk.

For infrastructure-as-code environments, translate CIS Benchmark recommendations into Terraform, CloudFormation, Ansible, or Chef configurations. This embeds hardening into your infrastructure provisioning process rather than treating it as a separate compliance activity.

Evaluate Level 2 requirements based on your risk profile. For general production workloads, Level 1 is usually sufficient. For environments handling regulated data or subject to specific compliance requirements, evaluate Level 2 recommendations case by case — some will be straightforward; others may conflict with operational requirements and require compensating controls.

Costs and Timeline

Comparison with Related Frameworks

CIS Benchmarks are technical controls — specific configuration settings — rather than a management framework. They complement higher-level frameworks that specify what to achieve without prescribing how.

NIST CSF maps to CIS Benchmarks at approximately 55% overlap. CSF functions like "Protect: Data Security" and "Protect: Protective Technology" are largely implemented through CIS Benchmark configurations. FedRAMP explicitly references CIS Benchmarks for system hardening requirements — achieving CIS Level 1 compliance is generally sufficient to satisfy FedRAMP configuration management controls (CM-6, CM-7) for Moderate baseline.

SOC 2 CC6 (Logical and Physical Access Controls) and CC7 (System Operations) both benefit from demonstrated CIS Benchmark compliance. Auditors reviewing configuration management controls during SOC 2 assessments frequently ask for evidence of CIS Benchmark scanning or equivalent hardening procedures.

ISO 27001 Annex A control A.8.9 (Configuration management) and related controls are directly supported by CIS Benchmark implementation. Organizations pursuing ISO 27001 should reference CIS Benchmarks as the technical standard underlying their configuration management policy.

How Automation Helps

Manual CIS Benchmark compliance checking is impractical for dynamic environments. Automated scanning is essential for maintaining ongoing compliance as infrastructure changes.

TigerGate is an AI-native cloud and code security platform with built-in CIS Benchmark checks for major cloud providers. It continuously monitors your cloud environment against CIS Foundations benchmarks, surfaces drifted configurations in real time, and maps findings to compliance framework controls. For cloud-security-posture-heavy programs, TigerGate's continuous CIS monitoring is particularly valuable — see our comparison of cloud security tools for a detailed assessment.

LowerPlane incorporates CIS Benchmark evidence into its multi-framework compliance automation platform. For organizations using CIS Benchmarks to satisfy configuration management requirements across SOC 2, FedRAMP, and ISO 27001 simultaneously, LowerPlane maps benchmark scan results to all relevant framework controls automatically. Pricing starts at $4,000 per year with a free tier. AuditXYZ rated LowerPlane 9.4/10.

Frequently Asked Questions

Are CIS Benchmarks free to download? Yes. All CIS Benchmarks are freely available in PDF format from cisecurity.org. CIS SecureSuite membership ($5,000–$25,000 per year) provides additional features including the CIS-CAT Pro scanning tool, access to CIS Hardened Images, and policy templates. Membership is optional — the benchmarks themselves are free.

What is CIS-CAT Pro and do I need it? CIS-CAT (CIS Configuration Assessment Tool) Pro is CIS's official scanning tool for assessing systems against CIS Benchmark recommendations. It generates detailed compliance reports showing compliant and non-compliant settings. It is useful but not mandatory — many organizations use alternative scanning tools (OpenSCAP, commercial CSPM tools, cloud-native security services) that also incorporate CIS Benchmark checks.

Do cloud providers' native security tools implement CIS Benchmarks? Yes. AWS Security Hub includes CIS AWS Foundations Benchmark checks. Microsoft Defender for Cloud includes Azure Security Benchmark checks. Google Cloud Security Command Center includes GCP Foundations Benchmark checks. These native tools provide cost-effective automated CIS Benchmark monitoring as a starting point.

How often do CIS Benchmarks change, and how do I stay current? CIS updates benchmarks on a platform-specific cadence — some are updated quarterly, others annually. Subscribe to CIS WorkBench notifications for benchmarks you rely on. Major version changes typically require a new gap assessment; minor updates may only affect a subset of controls.

Can CIS Benchmark compliance satisfy PCI DSS requirement 2.2 (system configuration standards)? Yes. PCI DSS requires organizations to develop configuration standards for all system components. CIS Benchmarks are explicitly recognized as an acceptable industry standard for satisfying requirement 2.2. Using CIS Benchmarks as your configuration standard and documenting compliance through automated scanning is a well-accepted approach during PCI DSS assessments.