Getting started with Prowler marks a pivotal step in enhancing your cloud security posture management (CSPM). As an open-source tool, Prowler empowers technical professionals to perform comprehensive security assessments, audits, and incident response across major cloud providers like AWS, Azure, and GCP, as well as Kubernetes environments. This article will guide you through the initial setup, core functionalities, advanced usage, and integration strategies to effectively leverage Prowler in your security operations.

Understanding Prowler’s Core Capabilities and Architecture

Prowler’s primary function is to identify misconfigurations and potential vulnerabilities within your cloud infrastructure by evaluating it against a vast array of security best practices and compliance frameworks. These include benchmarks from CIS (Center for Internet Security), PCI DSS, HIPAA, GDPR, and many more. Its design caters specifically to the dynamic nature of cloud environments, allowing for both point-in-time assessments and continuous monitoring.

At its core, Prowler is a Python-based command-line interface (CLI) tool. It operates by making authenticated API calls to your cloud provider’s services. For instance, in AWS, it heavily relies on the boto3 library to interact with various AWS services (EC2, S3, IAM, VPC, etc.), retrieve configuration details, and then apply its extensive set of checks against these configurations. Each check is designed to validate a specific security control, such as “S3 buckets should not be publicly accessible” or “MFA should be enabled for root account.”

Prowler organizes its checks into groups (e.g., cis_1.2, pci_3.2.1) and services (e.g., s3, iam, ec2). This modular approach allows for targeted scans, reducing the noise and focusing on relevant areas for specific audit requirements. The tool’s architecture is lightweight and extensible, making it a flexible addition to any cloud security toolkit.

Key Concept: Prowler doesn’t fix issues directly by default. It identifies them. While it has some remediation capabilities (e.g., audit and fix modes for specific checks), its primary strength lies in its comprehensive auditing and reporting.

Prowler interacts with your cloud environment by making authenticated API requests to cloud provider services (e.g., EC2, S3, IAM for AWS). It retrieves configuration data from these services, processes this data to evaluate security checks, and then generates comprehensive security findings and reports.

Initial Setup and Basic Execution

To begin using Prowler, you’ll need to set up your environment with the necessary prerequisites and install the tool.

Prerequisites

1. Python 3.8+: Prowler is built on Python. Ensure you have a compatible version installed.
2. pip: Python’s package installer, used for managing dependencies.
3. Cloud Provider CLI/SDK configured:
   • AWS: aws-cli configured with appropriate credentials (~/.aws/credentials or environment variables).
   • Azure: az cli logged in.
   • GCP: gcloud cli logged in and project selected.
   • Kubernetes: kubectl configured to connect to your cluster.

Installation

Prowler can be installed by cloning its GitHub repository or via pip. Cloning is often preferred for easy access to the latest development or specific versions.

# Clone the Prowler repository
git clone https://github.com/prowler-cloud/prowler.git
cd prowler

## Install dependencies
pip install -r requirements.txt

Alternatively, for a simpler installation:

## Install via pip
pip install prowler

Authentication and Permissions

Crucial: Prowler requires read-only permissions to query your cloud resources. Granting least privilege is paramount. For AWS, this typically involves an IAM role with policies like SecurityAudit or a custom policy tailored to Prowler’s specific API calls. Running Prowler with administrative credentials is a significant security risk and should be avoided.

To specify AWS credentials, Prowler will honor the standard AWS credential chain: environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY, AWS_SESSION_TOKEN), shared credential files (~/.aws/credentials), and IAM roles attached to EC2 instances or assumed via STS^[1].

Your First Scan

Once installed and authenticated, you can run a basic scan. By default, Prowler will run all checks against all supported services in all enabled regions for your authenticated account.

## For AWS
prowler aws

## For Azure (requires specifying subscription ID)
prowler azure --subscription <YOUR_SUBSCRIPTION_ID>

## For GCP (requires specifying project ID)
prowler gcp --project <YOUR_PROJECT_ID>

## For Kubernetes
prowler kubernetes

The output will be streamed to your console, showing each check, its status (PASS, FAIL, INFO, NOT_APPLICABLE), and a brief description. This initial scan provides a broad overview of your security posture.

Advanced Usage and Customization

While a full scan is useful, Prowler’s power truly shines with its ability to target specific areas, control output, and integrate into complex environments.

Targeting Specific Services, Checks, or Groups

To focus your audit, you can specify which services, checks, or groups of checks Prowler should execute. This is particularly useful for compliance audits or when investigating specific security concerns.

• By Service: Scan only s3 and iam services.

  prowler aws --services s3 iam
  

• By Check ID: Run a specific check, e.g., s3_bucket_public_access_block.

  prowler aws --checks s3_bucket_public_access_block
  

• By Group: Run all checks related to a specific compliance framework, e.g., cis_1.5_aws.

  prowler aws --groups cis_1.5_aws
  

  You can combine these options, for instance, to run specific CIS checks on S3.

Output Formats

Prowler supports various output formats, allowing you to integrate its findings into different tools and workflows. The default output is plain text, but you can specify formats like JSON, CSV, HTML, JUNIT XML, and even directly push findings to AWS Security Hub.

To generate output in multiple formats:

prowler aws --checks s3_bucket_public_access_block --output-modes json html --output-filename s3_public_access_audit

This command will generate s3_public_access_audit.json and s3_public_access_audit.html files.

Multi-Account and Multi-Cloud Scans

For organizations with complex cloud landscapes, Prowler supports scanning multiple accounts (AWS Organizations), multiple subscriptions (Azure), or multiple projects (GCP).

For AWS Organizations, Prowler can assume a role in each member account from a delegated master account. This is configured using the --organizations-role flag, specifying the role name to assume in each child account.

prowler aws --organizations-role AWSControlTowerExecution --output-modes json --output-filename org_audit

This enables a centralized security team to audit the entire organizational structure efficiently^[2].

Custom Checks

Prowler’s extensibility allows organizations to define their own custom security checks, tailored to internal policies or specific business requirements not covered by default checks. Custom checks are typically defined in Python or YAML and follow a specific structure, enabling Prowler to dynamically load and execute them alongside its built-in checks. This is a powerful feature for enforcing internal governance.

Integration and Automation

Integrating Prowler into your existing DevSecOps pipelines and security workflows transforms it from a manual auditing tool into a continuous security enforcement mechanism.

CI/CD Pipeline Integration

Embedding Prowler into your Continuous Integration/Continuous Deployment (CI/CD) pipelines can prevent insecure configurations from being deployed. For instance, Prowler can be run as a gate before resource provisioning (e.g., Terraform apply) or after deployment to validate the security posture of newly deployed infrastructure.

In a typical CI/CD integration, the workflow proceeds as follows: Developer commits or pull request merges trigger the CI/CD pipeline (e.g., GitHub Actions, GitLab CI), which then builds and tests the code. After the build and test phase, a Prowler scan step is executed using commands like prowler aws --output-mode junit --exit-code-on-fail. The pipeline then evaluates the scan results, and if Prowler finds critical issues, it fails the pipeline, preventing deployment. Only when the security checks pass does the application get deployed to the cloud environment.

Using the --exit-code-on-fail option, Prowler can return a non-zero exit code if it finds failing checks, effectively stopping the pipeline. This is a robust way to enforce security policies pre-deployment.

Security Hub Integration

For AWS users, Prowler can send its findings directly to AWS Security Hub using the --security-hub flag. Security Hub acts as a central aggregator for security alerts and findings from various AWS services and partner solutions. Integrating Prowler findings into Security Hub provides a unified view of your security posture alongside findings from GuardDuty, Macie, Inspector, and others^[3]. This streamlines incident response and compliance reporting.

Reporting and Alerting

Beyond Security Hub, Prowler’s JSON output can be ingested by various Security Information and Event Management (SIEM) systems like Splunk, ELK Stack, or dedicated security dashboards. This enables security teams to:

• Visualize trends: Track improvements or degradations in security posture over time.
• Trigger alerts: Configure alerts for new critical findings or regressions.
• Automate workflows: Initiate remediation actions or create tickets in issue tracking systems (Jira, ServiceNow) based on Prowler output.

The choice between manual, scheduled, or real-time scanning involves trade-offs. While real-time monitoring offers immediate feedback, it can be resource-intensive. Scheduled scans (e.g., daily or weekly via cron jobs or AWS Lambda) provide a good balance between currency of findings and operational overhead.

Conclusion

Prowler stands out as an indispensable open-source tool for cloud security auditing and compliance. Its comprehensive check library, multi-cloud capabilities, and flexible output options make it suitable for a wide range of technical roles, from security engineers to DevOps practitioners. By starting with basic scans and progressively integrating Prowler into your CI/CD pipelines, leveraging its advanced features like custom checks and Security Hub integration, you can significantly elevate your organization’s cloud security posture. Embracing tools like Prowler is not just about identifying vulnerabilities; it’s about fostering a culture of continuous security, ensuring that your cloud infrastructure remains resilient against evolving threats.

References

[1] Prowler-cloud. (n.d.). AWS Credentials. Available at: https://docs.prowler.cloud/en/latest/references/aws-credentials/ (Accessed: November 2025)

[2] AWS. (n.d.). AWS Organizations. Available at: https://aws.amazon.com/organizations/ (Accessed: November 2025)

[3] Amazon Web Services. (2023). AWS Security Hub User Guide. Available at: https://docs.aws.amazon.com/securityhub/latest/userguide/securityhub-ug.pdf (Accessed: November 2025)

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