CFRipper vs Fairwinds Polaris

CFRipper is a free, open-source Python library and command-line security analyzer for AWS CloudFormation templates. It examines template files to help keep vulnerable infrastructure from reaching production. The CLI accepts templates as arguments and can return text or JSON findings, with an option to save results in an output folder. Example findings include wildcard principals and IAM role policies that grant excessive permissions. Rules can be configured with a rules file and filters folder, and users can add plugins for their own compliance checks. Documented exit codes distinguish successful scans, scanning errors, invalid templates, and unhandled exceptions. CFRipper runs on Linux, macOS, Windows, or as self-hosted software. The project uses uv for dependencies, provides installation instructions for those operating systems, and is distributed under the Apache License 2.0. Its analysis scope is CloudFormation; Terraform and Kubernetes are not supported.

Fairwinds Polaris is an open source policy engine for validating and remediating Kubernetes resource configuration. It includes more than 30 built-in policies, and teams can add their own using JSON Schema. Checks cover security practices such as least privilege, privilege escalation, root execution, and host IPC or PID settings, along with resource requests and limits, readiness and liveness probes, and image tags. Polaris can run as a dashboard, an admission controller, or a command-line tool for checking local YAML files in CI/CD. Its validating webhook rejects workloads that trigger danger-level checks; warning-level findings pass and appear in the dashboard or webhook logs. A mutating webhook or command-line run can automatically remediate supported issues, including missing limits and probes and some unsafe security settings. The dashboard can audit local files or connect to a live cluster, and can be installed with kubectl or Helm. The validating webhook requires a valid TLS certificate. Polaris is free and runs on Linux, macOS, Windows, web, and self-hosted environments.