cfn-nag vs kube-score

cfn-nag is free, MIT-licensed software that scans AWS CloudFormation templates for patterns that may indicate insecure infrastructure. It checks for overly permissive IAM policies and security-group rules, disabled access logging or encryption, and password literals. The scanner accepts JSON, .template, YAML, and YML files, and recursively processes subdirectories when given a directory. Results print to standard output, with JSON output available; failures return a non-zero exit code while warnings return success. Installation is documented through RubyGems and Homebrew, with Ruby 2.5 or later required for gem installation. A Dockerfile and Docker Hub image are provided. cfn-nag can run in GitHub Actions and AWS CodePipeline. Profiles, deny lists, per-resource suppressions, and custom rules support policy tailoring. Static analysis needs supplied parameter values to assess them and does not inspect false Fn::If outcomes by default.

kube-score statically analyzes Kubernetes object definitions and recommends changes intended to improve application security and resilience. Its checks cover container limits, NetworkPolicy targeting, PodDisruptionBudget, Pod anti-affinity, container probes, security context, and stable APIs. Optional checks include matching resource requests and limits, container ports, and seccomp profile configuration. You can configure tests to be ignored or enabled globally or for individual objects. kube-score works with Helm, Kustomize, static YAML files, Docker, and resources retrieved from a Kubernetes cluster. Its browser demo accepts Kubernetes YAML or JSON and, according to the maker, processes it in the browser without sending data to a server. Local options include prebuilt binaries for Linux, macOS, and Windows, along with Docker, Homebrew, and Kubernetes Krew. Output formats include human-readable, JSON, CI, and SARIF. In CI/CD, critical errors return exit code 1; warnings can also be set as the exit threshold. The free, MIT-licensed project recommends analyzing all applications deployed to the same namespace together. Building from source requires Go 1.21 or later.