Top 10 IaC Security Best Practices

What Is Infrastructure as Code (IaC) — and Why It Changes Security

Conceptually, Infrastructure as Code (IaC) is a software-defined infrastructure and a part of the DevOps approach that allows an organization's infrastructure (servers, databases, resources, networks, etc.) to be described as code using declarative/imperative IaC templates. IaC provides valuable benefits such as automation, consistency, and speed.

Companies most often use IaC tools such as Terraform, Ansible, and AWS CloudFormation. Terraform allows you to describe and automatically create infrastructures across different clouds and environments, Ansible offers automation and the ability to configure servers and deploy applications using simple scenarios, and AWS CloudFormation allows you to create and manage cloud infrastructure using templates.

When discussing security and how the IaC approach impacts it, the following aspects are worth mentioning:

• Increased infrastructure transparency due to the fact that all configurations are stored in a repository and can be verified as infrastructure code

• Reduced human error through automation and the risk of configuration errors making it into deployment

• Automation of security processes, such as automatic IaC scanning with every code change

• The ability to block insecure configurations before they reach production

Overall, Infrastructure as Code improves infrastructure manageability and protection through automation, version control, security checks, and, most importantly, code management.

Why IaC Security Is Critical in Modern Cloud Environments

Infrastructure as Code (IaC) improves security by making infrastructure configurations consistent, version-controlled, and reviewable before deployment. Instead of manually configuring cloud resources, teams can validate infrastructure definitions against security policies, detect misconfigurations early, and maintain an auditable history of every infrastructure change.

Speaking about the role of IaC security in modern cloud infrastructure, the most important factors to keep in mind are:

• Cloud misconfigurations are among the most common causes of data breaches, with 23% of all cloud security incidents in 2025 stemming from misconfigurations.

• Even a single configuration error can be replicated at scale, as a single IaC template may provision hundreds of cloud resources

Infrastructure as Code security enables teams to spot security issues before infrastructure reaches production, and it also allows security teams to extend visibility into infrastructure changes through version control and code reviews.

Effective security strategies and opportunities offered by the IaC approach include:

• Embedding security controls directly into infrastructure definitions. This shift into the IaC layer allows teams to address risk as they define resources, thus making security an integral part of infrastructure from the first line of code

• Implementing proactive security, as IaC security focuses on securing IaC templates and pipelines that define and provision resources before deployment. This allows teams to detect security vulnerabilities during planning before production begins and embed security controls in IaC scripts to ensure their infrastructure has the correct security settings from the start.

Critical IaC Risks and Weak Points Often Missed

IaC is a powerful tool, but it's not secure by default. While offering benefits, it also introduces new IaC risks, such as misconfigurations and secret leaks, which may often be a "hidden" security risk.

For example, in one case, a team used Terraform to create VPCs, subnets, IAM roles, and other resources, but failed to consider that the Terraform state file could store sensitive data (passwords, API keys, tokens, secrets). If an attacker were to gain access, this could allow access to infrastructure, databases, or privilege escalation. Auditing Terraform configurations, moving secrets to a dedicated secrets vault, encrypting a state file, and restricting access using the principle of least privilege prevented potential security issues.

If you want to enforce security, these weak points should be addressed first:

• Secrets in a state file, where passwords, keys, and other sensitive data can be stored in Terraform state, thus becoming an entry point for attackers

• Excessive IAM privileges, when a single compromised account can lead to the takeover of a large number of IaC resources

• Insecure default settings, such as open Security Groups, public S3 buckets, and a lack of encryption or logging

• Drift between code and the actual infrastructure, causing the team to lose control of the environment, and critical risks to go undetected until an incident occurs

Top Infrastructure as Code Security Best Practices

IaC usage provides valuable advantages, but it's worth implementing IaC security best practices to enjoy the benefits without significant security risks.

1. Use a Secrets Manager

These are among the most common IaC issues when teams store passwords, tokens, and API keys in Terraform files, variables, or repositories. If leaked, the state file could expose access to the company's databases and infrastructure.

The best solution is to use a secrets manager tool to store secrets centrally.

In one project, we discovered that the Stripe API key was stored in the Git history, which required rotating and revising all templates. This case illustrates the problem of storing secrets in code and the need to move them to a centralized repository.

2. Apply Least Privilege Across All IaC Resources

Developers may grant services and users extensive privileges to improve usability. However, if an account or service is compromised, hackers gain broad access to actions within the infrastructure, creating security threats.

To strengthen IaC security, teams must grant only the permissions necessary to perform a specific task and no more. Least privilege for all resources is the best solution here.

3. Secure Terraform State Files

Since Terraform state can contain sensitive data (IaC configurations, identifiers, and secrets), accessing the state file allows an attacker to obtain valuable information about the infrastructure and use it for malicious purposes.

Teams should store state files in a secure backend, enable encryption, and enforce the principle of least privilege.

We once configured Terraform so that the state file was encrypted in S3+KMS, secrets were retrieved from AWS Secrets Manager via a module, and a pre-commit review checked for any hardcoded secrets. This eliminated the need to store secrets in the code and increased cloud security against credential leaks. Furthermore, pre-commit checks helped identify security issues before changes were pushed to the repository.

4. Integrate IaC Scanning Early in the Pipeline

Infrastructure as Code security scanning is essential as it helps detect security issues, preventing errors in code after deployment. Automatic IaC scanning and secret verification in CI/CD before deployment helps reduce the risk of public resources, weak access settings, or other critical vulnerabilities reaching production.

In one of our cases, we added Terraform Plan review, Checkov, and secrets scanning in CI/CD, and the team began automatically identifying insecure configurations and accidentally added secrets during development. As a result, if the scan detected an issue, the pipeline was stopped until a fix was found, preventing vulnerable changes from reaching production.

5. Use Policy-as-Code to Enforce Standards Automatically

As infrastructure scales, security and compliance become more pressing, and manual approaches become more difficult. This can lead to situations where teams create resources with configurations that inherently violate internal policies or compliance. 

Policy-as-Code is among the best practices for IaC, as it allows for unifying security rules in code and automatically blocking any non-compliant changes.

 6. Vet and Sign Third-Party IaC Modules

Common IaC issues include external Terraform modules and templates being used without validation, which can lead to vulnerable modules making the infrastructure insecure and granting unnecessary privileges.

Teams must use only trusted sources, audit modules, and pin trusted versions. This is where the vet and sign practice is particularly effective.

7. Enable Drift Detection and Continuous Compliance

Sometimes developers may manually change resources through the cloud provider's console after deployment, causing the infrastructure to deviate from the IaC code. This complicates management and increases the likelihood of errors.

The way to address these IaC security risks is to regularly check the infrastructure for drift and automatically detect deviations from approved configurations.

8. Harden CI/CD Environments

CI/CD pipelines have broad permissions and access to secrets. This means that if compromised, malicious code can be injected or changes made to the infrastructure.

Hardening CI/CD environments involves implementing service account protection, isolating the environment, restricting access, and controlling secret usage.

9. Implement Change Management and Code Review for All IaC

If changes to infrastructure are made without sufficient review or approval, even a small coding error can lead to incorrect access settings and data leaks.

Using pull request processes, as well as mandatory review and documented approval of changes, is among IaC best practices.

10. Monitor Secret Usage and Resource Changes in Real Time

It's common for critical security threats and suspicious activity to go undetected until security incidents occur. Worst of all, a hacker can use stolen secrets or modify resources undetected for extended periods of time.

Monitoring how secrets are used, auditing infrastructure changes, and automated security feedback and alerts on suspicious events are ways to detect security issues and anomalies before they lead to a breach.

Tools and Frameworks for IaC Security

Let's look at the most useful IaC security tools based on their purpose.

Advanced Approaches to Strengthen IaC Security

In addition to Infrastructure as Code security best practices, teams can implement more advanced approaches to ensure infrastructure security at the process and architecture levels.

• Policy as Code. With Sentinel or OPA, developers can find errors and block the creation of resources that violate security or compliance requirements, ensuring Policy as Code governance and automatic enforcement of security policies. Teams should sign Terraform modules (Sigstore/Cosign) to build a robust policy governance framework with exceptions, approval workflows, and centralized policies to ensure consistent governance across large multi-cloud environments.

• Supply Chain Security for IaC Modules. With cryptographic signing and module provenance, teams can sign Terraform modules and verify their source before use, thus ensuring that the module is trusted. This helps minimize supply chain attacks.

• Continuous Drift Detection. This approach involves continuous monitoring of deviations between the IaC code and the actual infrastructure. The system detects drifts and automatically returns resources to the approved state, ensuring a secure infrastructure. By integrating drift detection with immutable infrastructure practices and combining it with cloud-native event monitoring, automated remediation workflows, and change approval policies, teams can minimize configuration drift, reduce manual intervention, and ensure alignment with the approved Infrastructure as Code definitions.

• Threat Modeling. Infrastructure threat modeling is extremely effective for proactively identifying potential attack vectors and security gaps, excessive privileges, unpatched vulnerabilities, etc. 

Organizational Foundations for Sustainable IaC Security

Integrating security isn't just about tools, but a comprehensive approach to processes. Here, key considerations include clear ownership, standardized workflows, ongoing training, and governance to ensure consistent security.

• Security Ownership. Not only security teams, but also developers, operations staff, engineers, and architects should be involved in identifying and resolving security challenges at all stages

• Standardized Workflows. It is essential to implement uniform security standards for creating, testing, reviewing, and deploying infrastructure code

• Security Training. Improving security awareness and conducting regular training helps minimize human errors and misconfigurations 

• Governance and Compliance. Security policies must be regularly reviewed and adapted to new threats and regulatory requirements to ensure long-term sustainability

Simple IaC Security Advice for Small Teams

Finally, the key thing, especially for small teams, is not to wait until you grow, but to start implementing basic practices right from the start. It's best to focus on the most critical aspects, namely:

• State file

• Secrets access 

• Least privilege policies

• Documentation (who has access to secrets, rotation, permissions)

It's also useful to introduce rules, such as auditing all secrets, rotating keys, and requesting an audit every 3 months.

Overall, the combination of automation, proper secret management, and regular audits enables secure IaC. Even implementing basic practices already significantly reduces risks.

You can ask engineers to conduct a "secret" audit to find hardcoded secrets, check state file settings, and integrate scanners before merging. At Jappware, we help businesses implement security and provide consulting to strengthen their defenses. You can reach out to us for security expertise.