Quick Start Guide to IaC Security

Infrastructure-as-Code (IaC) is a powerful way to automate and scale the provisioning and configuration of IT resources. But it also presents some challenges – not least in the realm of security. To leverage IaC to full effect, organizations must understand which types of security risks IaC can introduce or exacerbate. They must also integrate IaC security protections into their software development and configuration management practices.

This article provides guidance on how to make the most of IaC while also ensuring adequate IaC security. It explains what IaC means, why it matters for security, and how to secure IaC templates reliably and efficiently.

What is Infrastructure-as-Code?

IaC is a technique that uses code to manage the provisioning and configuration of IT resources – such as servers or application deployments. IaC works by allowing admins to write code files (known as templates) that define how a resource should be configured. They can then apply the configuration automatically.

IaC provides several critical benefits, including:

• Efficiency: IaC saves time by avoiding the need for admins to configure resources manually.
• Scalability: Because the same code-based configuration can be applied to multiple resources, IaC helps to scale provisioning and management processes. Admins can configure a thousand servers in little more time than it would take them to configure one.
• Consistency: IaC ensures consistent configurations and mitigates the risk of oversights caused by human error when provisioning resources.
• Built-in version control: IaC templates can be managed using version control software, such as Git. This allows teams to keep track of how configurations change over time and to revert to an earlier version quickly if desired.

The impact of IaC code on security

In some respects, IaC offers inherent security benefits. Its main advantage from a security perspective is that IaC enables consistent configurations. Resources that are provisioned based on a template will be secure if the configuration defined in the template is secure.

But that’s a big if – and therein lies the core security challenge that IaC presents. When IaC templates are insecure, they can cause insecure configurations to proliferate across any resources to which they are applied.

For instance, imagine an IaC template that a team uses to provision Amazon S3 storage buckets (a type of resource in the Amazon cloud that can store data). Imagine, too, that due to an oversight on the part of the admin who creates the template, it makes the buckets readable by anyone on the Internet.

If this happens, the data inside any S3 buckets that the organization provisions using the template would be publicly accessible. This could lead to the exposure of sensitive information in the event that the buckets contain data that the business intends only for internal use.

Put simply, IaC is only as secure as the templates used to manage resource configurations – and it’s all too easy to introduce security risks into templates, and then spread those risks across an entire environment.

Best practices for securing IaC

To benefit from IaC without letting IaC templates become the weakest link in their security posture, businesses must employ adequate IaC security protections. Here’s a look at core IaC security best practices.

Scan IaC code templates

Above all, teams should deploy IaC code scanning tools. Infrastructure as code tools automatically analyze IaC templates for risks, such as resources that are configured for public access even though they may contain sensitive data.

By comprehensively scanning templates whenever developers create them, businesses can identify IaC security risks before they apply to production resources.

Integrate IaC tools into CI/CD

To minimize friction between software development and security processes, it’s best practice to integrate IaC tools into CI/CD pipelines. This means that template scanning should take place as one part of the broader set of automated tests that occur during software development.

Integrated IaC security helps to ensure that developers catch IaC security risks early, when they are easier to fix. It also reduces the chance that IaC security problems that remain undiscovered until the later stages of the software development life cycle will delay software releases.

Avoid hard-coded credentials in IaC templates

When provisioning resources, it’s often necessary to provide passwords, API keys, or other sensitive data. Embedding this information directly into IaC templates may be tempting because it’s convenient; however, teams should avoid this practice because it can lead to the leakage of secrets (meaning sensitive access credential information).

A better approach is to store secrets inside a secrets manager tool, and then reference the secrets within IaC templates without hard-coding them directly.

Apply immutable infrastructure techniques

Immutable infrastructure refers to IT resources that are destroyed and recreated whenever updates are necessary, as opposed to being updated in place. In the context of IaC security, immutable infrastructure can help reduce the risk of assuming that a resource is subject to one configuration when in reality it has changed.

For example, imagine that a team provisions an S3 bucket using a template where public access to the bucket is not allowed. Later, someone manually changes the bucket’s access settings to enable public access. In this case, the organization may assume that data in the bucket is not publicly readable even though it is.

To mitigate this risk, organizations can establish rules mandating that admins implement configuration changes by creating a new resource, based on a new template, instead of updating resources in place.

Version-control IaC templates

Although using version control software to manage IaC code templates is not strictly necessary to take advantage of IaC, it’s a best practice from a security perspective because it makes it easy to detect changes to templates that could impact security.

For instance, if a developer modifies an IaC template by adding an access credential, version control tools would make it easy to determine exactly when the change took place and which resources may have been impacted by it. Without version control, the team would only have insight into the state of the most recent version of the template, with no visibility into the configuration status of the template (or resources that were provisioned based on it) over time.

Securing IaC with Checkmarx One

As a core capability within Checkmarx One, IaC security scanning features strengthen infrastructure security through advanced scanning, proactive vulnerability identification, and robust misconfiguration detection.
See for yourself by requesting a demo. Or, learn more by reviewing our IaC solution brief.