Understanding CIS Cloud Benchmarks
The Center for Internet Security (CIS) Benchmarks are prescriptive, consensus-based security configuration standards developed by a consortium of security experts, government agencies, and technology companies. CIS Benchmarks provide detailed technical guidance for hardening systems, applications, and cloud platforms.
CIS Benchmarks are different from broader frameworks like NIST or CSA. While those frameworks describe what security controls you should implement, CIS Benchmarks describe specifically how to implement those controls. This makes CIS Benchmarks more technical and prescriptive.
CIS Cloud Benchmarks specifically address cloud platform security. Major cloud providers have corresponding benchmarks: AWS Foundations Benchmark, Azure Foundations Benchmark, and Google Cloud Platform Foundations Benchmark. These benchmarks provide step-by-step guidance for configuring cloud platforms securely.
CIS Benchmarks are developed through a consensus process where security experts collaboratively develop the benchmarks. This ensures benchmarks reflect the collective expertise of leading security professionals and organizations.
How CIS Benchmarks Work
Each CIS Benchmark is organized into control areas that address different security aspects. For example, the AWS Foundations Benchmark includes controls for Identity and Access Management, Storage, Logging, Networking, and Compliance.
Each control in a CIS Benchmark includes:
A control number and title describing the security objective (e.g., "1.1 Avoid the use of root account").
A description of the security risk the control addresses and why the control is important.
A detailed implementation procedure explaining exactly how to configure the system to comply with the control. These procedures are often step-by-step instructions.
Assumptions and dependencies noting any prerequisites for implementing the control.
An impact assessment describing what impact implementing the control might have on operations or performance.
Default values for automated scanning tools that will evaluate compliance with the control.
CIS Cloud Benchmarks for Major Platforms
AWS Foundations Benchmark
The AWS Foundations Benchmark provides guidance for securing AWS accounts and cloud resources. Controls address identity and access management (IAM roles, policies, MFA), storage (S3 bucket policies, encryption), logging and monitoring (CloudTrail, CloudWatch), networking (security groups, VPCs, VPC Flow Logs), and compliance.
AWS Foundations Benchmark is widely used by organizations deploying to AWS. Many organizations use CIS Benchmark compliance as part of their AWS security strategy.
Azure Foundations Benchmark
The Azure Foundations Benchmark provides guidance for securing Azure subscriptions and resources. Controls address role-based access control (RBAC), data protection (encryption, key vault), logging and monitoring (activity logs, diagnostic logs), networking (network security groups, firewalls), and compliance.
Azure Foundations Benchmark is the standard for Azure security hardening and is frequently referenced in Azure governance policies.
Google Cloud Platform Foundations Benchmark
The GCP Foundations Benchmark provides guidance for securing Google Cloud projects and resources. Controls address identity and access management (IAM roles, service accounts), data protection (encryption, key management), logging and monitoring (Cloud Logging, Cloud Audit Logs), networking (firewall rules, VPC), and compliance.
GCP Foundations Benchmark guides GCP security implementation and is often used to establish GCP governance standards.
Levels and Scoring
CIS Benchmarks classify controls into levels based on impact and implementation difficulty.
Level 1 controls are foundational security controls that can typically be implemented with minimal impact on operations. These controls address basic security hygiene and are generally considered essential. Level 1 controls should typically be implemented across all systems.
Level 2 controls provide more advanced security but may require more significant operational changes. Level 2 controls are recommended for organizations with higher security requirements or in sensitive industries.
Some benchmarks also include Level 3 controls for highly sensitive environments requiring the most restrictive security configurations.
Organizations often start by implementing Level 1 controls then progress to Level 2 as they mature their security practices.
Using CIS Benchmarks in Cloud Security Assessments
Cloud security assessments frequently evaluate compliance with CIS Benchmarks. Assessment tools often include CIS Benchmark checks as part of their assessment methodology.
When an assessment identifies a CIS Benchmark gap, it means your cloud environment does not comply with the specific control defined in the benchmark. For example, if an assessment finds that CloudTrail logging is not enabled (AWS Benchmark control 2.1), this is a gap in logging and monitoring.
CIS Benchmarks help organizations understand what specific configurations are considered secure and provide clear guidance on how to achieve compliance.
Automated CIS Benchmark Scanning
One advantage of CIS Benchmarks is that they're highly specific and technical, making them well-suited for automated scanning. Tools like AWS Security Hub, Azure Security Center, and various third-party tools automatically scan your cloud environment against CIS Benchmark controls and report compliance status.
Automated scanning provides several benefits. First, it provides ongoing monitoring of CIS Benchmark compliance rather than waiting for periodic manual assessment. Second, it identifies specific non-compliant resources that need remediation. Third, it tracks compliance trends over time.
Many organizations implement continuous CIS Benchmark scanning as part of their security operations, checking compliance daily or continuously rather than waiting for periodic assessment.
Differences from NIST and CSA
While CIS Benchmarks, NIST Cybersecurity Framework, and CSA Cloud Controls Matrix all address security, they serve different purposes.
NIST provides high-level guidance on organizing security programs and addressing all important security areas. It's broader and more governance-focused.
CSA provides cloud-specific controls addressing cloud-unique security challenges. It's designed specifically for cloud environments but at a higher level than CIS.
CIS provides specific technical implementation guidance for particular platforms. It's narrower but more prescriptive.
Organizations often use all three. NIST and CSA help identify what controls to implement, and CIS provides specific implementation guidance.
CIS Controls vs CIS Benchmarks
It's important not to confuse CIS Controls with CIS Benchmarks. CIS Controls are a different set of recommended security practices organized into 18 foundational controls. While CIS Controls provide good general security guidance, CIS Benchmarks are what organizations use for cloud platform hardening.
Implementing CIS Benchmarks
Organizations implementing CIS Benchmarks typically follow a structured approach.
First, select the appropriate benchmark for your cloud platform. If you use AWS, start with AWS Foundations Benchmark. If you use Azure, use Azure Foundations Benchmark.
Second, review benchmark controls and identify which are applicable to your environment. Some controls may not apply to your specific architecture or use case.
Third, prioritize controls for implementation. Level 1 controls should typically be prioritized. Additional considerations include whether controls address your highest-risk areas and the effort required for implementation.
Fourth, implement controls according to benchmark guidance. The detailed procedures in benchmarks guide exact implementation.
Fifth, verify compliance through manual review or automated scanning tools.
Sixth, establish monitoring and alerting to detect drift (changes that make systems non-compliant). Continuously enforcing controls is important because cloud configurations can change.
Finally, periodically review compliance and update implementations as your environment changes.
Challenges with CIS Benchmarks
While CIS Benchmarks are valuable, they present some challenges. Some controls may be overly restrictive for particular organizations, affecting operations more than the benefit warrants. Some controls may conflict with other organizational requirements. Implementing and maintaining CIS Benchmark compliance requires ongoing effort.
The key is using CIS Benchmarks as guidance while making thoughtful decisions about which controls are appropriate for your organization and risk profile.
CIS Benchmarks and Compliance
Many compliance frameworks reference or align with CIS Benchmarks. For example, SOC 2 controls often align with CIS Benchmarks. Organizations working toward compliance certifications should understand how CIS Benchmarks support their compliance objectives.
CIS Cloud Benchmarks provide specific, technical guidance for hardening cloud platforms. By using CIS Benchmarks to guide cloud configuration and continuously monitoring compliance, organizations can implement cloud security configurations aligned with industry best practices.
