However, new security challenges emerge despite the significant advantages of speed and scalability that IaC offers. Incorrect configurations and vulnerabilities in infrastructure templates can quickly propagate throughout the application stack. Therefore, adhering to best security practices for IaC and integrating relevant tools directly into your CI/CD pipeline is crucial. This article discusses critical aspects of Infra-as-Code security, including the best open-source IaC security tools to integrate into your pipeline.

What Is Infrastructure as Code (IaC) & What Are Its Benefits?

Infrastructure as Code (IaC) is an approach that facilitates the automation and management of IT infrastructure using code rather than manual processes. Within the IaC framework, configuration files are created with specifications for the desired infrastructure. This accelerates the deployment process and enhances the reproducibility and scalability of infrastructure setups. It also allows for version control of infrastructure, similar to software code, enabling better tracking of changes and quicker rollback in case of issues. Furthermore, it simplifies the editing and distribution of configurations, ensuring a consistent environment deployment each time.

The key advantages of IaC include:

• Accelerated infrastructure deployment: Automated processes result in quicker deployment than manual configuration.
• Reduced risk of errors: Automation lowers the likelihood of human errors compared to manual operations.
• Uniform infrastructure through standard templates: Templates promote consistency in the configurations of deployed systems.
• Elimination of issues with configuration drift: Automation through templates prevents configurations from deviating.

IaC empowers companies to scale their IT infrastructure flexibly and launch new applications and services more rapidly. Automation not only saves time but also conserves resources during the implementation of new services.

IaC Security Risks to Be on the Lookout For

When working with Infrastructure as Code (IaC), it's easy to make mistakes that can open doors to hackers. To safeguard your systems, awareness and proactive measures are crucial. Let's examine five key risks and how to minimize them.

• Incorrect settings in IaC templates: hard-coded passwords, outdated software versions, and code errors are all potential security vulnerabilities. It's critical to rigorously test templates, monitor updates, and prevent secrets from being embedded in the code.
• Insecure storage of secrets: Access keys and database passwords within templates are susceptible to leaks. In the event of unauthorized access, the consequences can be severe. Specialized tools should be employed for secure secret management.
• Excessive user permissions: When everyone has unrestricted access, the risk of a breach increases. Adhering to the principle of least privilege and regularly auditing access settings are essential.
• Unprotected state files: state files contain valuable information for attackers. Encrypting and restricting access to these files is necessary to prevent leaks.
• Lack of testing and validation: untested code is unreliable code. Implementing DevSecOps practices and using automated tools to check code for vulnerabilities are recommended.

By following best practices in IaC usage, significant risks can be substantially reduced, safeguarding the infrastructure.

What Are the Best Practices for Robust IAC Security?

IAC security best practices that IT teams and organizations should implement to mitigate risk include:

Scan Infrastructure Code for Vulnerabilities

Code describing the infrastructure and its configurations should be scrutinized as thoroughly as the core application code. Otherwise, vulnerabilities in infrastructure code may grant malicious actors access to databases, application servers, and other critical components.

Utilize security scanners for IaC that can check infrastructure templates for common errors. For example, improper network ACL configurations could make a database publicly accessible from the internet. Static analysis of templates will help identify such issues before deployment.

Automate Security Checks in the CI/CD Pipeline

Integrating IaC security scanning into the continuous delivery system means that developers can identify and address issues at early stages. For instance, configure scans for pull requests and development branches to identify potential problems, preventing the introduction of vulnerabilities into the main code branch. Complete IaC security checks can also be run during the application build phase in the CI/CD system. This approach is much more effective than attempting to fix issues in the operational infrastructure.

Detect and Prevent Configuration Drift

A common issue with IaC is the gradual divergence of actual configurations from those described in the code templates. Configuration drift occurs due to ad-hoc changes made directly to the running infrastructure, administrative errors, glitches during stack updates, and more. Over time, these deviations from the original templates can accumulate and pose serious security issues.

To avoid this, regularly compare the current configuration state with the code that describes it. This way, drifts can be identified and rectified early, preventing the environment from deviating significantly. Various configuration analysis and tracking tools are available for this purpose.

Protect Secrets and Credentials in Infrastructure Code

Hard-coded access keys, passwords, tokens, and other security secrets in infrastructure templates pose significant security risks to the organization. If such code becomes publicly accessible, malicious actors can gain ready access to your systems and data.

Therefore, safeguarding secrets and confidential data when using IaC is critically essential. All confidential and sensitive data should be kept by managers and retrieved as needed. Scanning infrastructure code for inadvertently left hard-coded secrets should also be part of the security strategy.

Regular Audit of Access Rights and Privileges

When using IaC, the entire infrastructure and its configurations are defined by code. Consequently, access and permissions to modify this code must be tightly controlled. Regularly audit access rights for all employees and integrations with the ability to edit infrastructure code. Ensure that the principle of least privilege is followed everywhere — unnecessary permissions can lead to unwanted changes due to errors or compromise of a single account.

It is also crucial to track the access lifecycle for terminated employees and old integrations — their outdated keys and tokens should be promptly revoked when no longer required. Failure to do so creates potential entry points for attacks.

Apply DevSecOps Principles for Security Assurance

DevSecOps is an approach to software development where security practices are integrated at all product life cycle stages. The same principles apply to Infrastructure as Code:

• Shift Left: Start thinking about infrastructure security at the earliest stages, even during the architecture design phase.
• Continuity: Regularly scan code, configurations, and environments for vulnerabilities. Automate these checks in CI/CD.
• Infrastructure Code is Still Code: Treat infrastructure templates like core application code regarding checks, testing, and reviews.
• Defensive Design: Develop the infrastructure with security in mind from the beginning, including separating environments and services, encrypting data, and restricting default access.
• Isolation and Segmentation: Divide the infrastructure into isolated segments based on purpose and criticality levels. This practice aids in localizing potential attacks.

This approach maximizes the security of both the infrastructure and the underlying code. Security becomes an integral part of the process, not an add-on after the fact.

What Are the Best Open-Source IaC Security Tools?

Numerous open-source tools assist developers in writing secure and reliable Infrastructure as Code (IaC) for cloud platforms. Let's explore the most useful ones and our experience using each. All mentioned tools are free and open-source, significantly reducing the risks of deploying Infrastructure as Code.

TFLint

TFLint is a linter that analyzes Terraform code and identifies potential errors or unsafe practices before deployment. It checks syntax, logic, the usage of deprecated functions, and more. TFLint is extendable with plugins for additional rules and organizational policies, helping to implement Infrastructure as Code securely by detecting issues early.

Infracost

Infracost is an open-source tool for estimating the cost of cloud infrastructure based on Terraform, CloudFormation, and other templates. It provides a detailed cost breakdown for each resource, helping developers understand the financial implications of infrastructure changes.

Checkov

Checkov scans Infrastructure as Code files for security errors and violations of best practices. It utilizes a library of pre-defined policy checks and supports custom rule additions. Checkov integrates well into CI/CD pipelines for automated analysis.

TFSEC

TFSEC focuses on detecting vulnerabilities in Terraform code through static analysis for compliance with security best practices. It checks IaC files for network security issues, access configuration errors, and encryption problems. TFSEC is convenient for automated checks in CI/CD before applying to production, preventing the introduction of risky configurations.

Regula

Regula scans Infrastructure as Code configurations for security gaps and compliance violations. It supports standards like CIS, NIST, and HIPAA and allows writing custom rules based on organizational policies. It covers major cloud platforms and IaC formats, including Terraform, CloudFormation, and Kubernetes.

Terraform-docs

Terraform-docs generates documentation for Terraform code in various formats. It extracts resource and variable descriptions from code comments, keeping documentation up-to-date. It simplifies infrastructure audit and management by automating technical documentation creation with code changes.

Terratest

Terratest is a framework for automating the testing of Infrastructure as Code in Terraform, Packer, and Docker. It supports various tests, including module unit tests, integration testing, end-to-end tests, static analysis, and error resilience checks.

Collectively, these tools provide a robust security and cost-effective approach to infrastructure as code.

Final Thoughts on Improving IAC Security with Open Source Tools & Best Practices 

Infrastructure as Code brings significant advantages in terms of speed and reliability when developing complex systems. However, it's essential to pay attention to security. By following the best practices mentioned above, risks can be minimized, and the infrastructure can be protected from potential attacks. The key is to start thinking about security early and embed corresponding processes directly into the development and deployment pipeline. This way, you can harness the full benefits of IaC without compromising security.