Applying SAST Tools to Infrastructure as Code — A Hands-On Look at Checkov

Why Infrastructure as Code Needs Static Analysis Too

Infrastructure as Code (IaC) — Terraform, Pulumi, OpenTofu, CloudFormation — turned infrastructure into something version-controlled, reviewable, and reproducible. But that also means a single misconfigured line — an S3 bucket left public, a security group open to 0.0.0.0/0, an unencrypted database — can be committed, merged, and deployed automatically, at scale, before anyone notices.

Static Application Security Testing (SAST) for IaC works the same way it does for application code: it parses configuration files without deploying anything, and flags insecure patterns against a known rule set. OWASP's list of Source Code Analysis Tools includes several options for this. This article focuses on Checkov, an open-source policy-as-code scanner built by Bridgecrew (now part of Palo Alto Networks), chosen here specifically because it's free, multi-cloud, and multi-framework — without relying on tfsec.

Why Checkov

Checkov scans IaC files and builds a graph representation of the resources and their relationships, then evaluates that graph against hundreds of built-in security and compliance policies.