Prowler Cloud Security Posture Assessment - Implementation Guide

Overview

Prowler is an open-source cloud security posture assessment tool that evaluates AWS, Azure, GCP, and Kubernetes environments against security best practices. This guide provides practical implementation steps for security engineers.

Key Features

• Multi-cloud support: AWS, Azure, GCP, Kubernetes

• 400+ security checks across multiple frameworks (CIS, NIST, PCI DSS, GDPR)

• Multiple output formats: JSON, CSV, HTML, ASFF

• CI/CD integration: GitHub Actions, Jenkins, GitLab

• Custom checks: Python-based extensibility

Installation Methods

Quick Start - Docker

AWS scan:

docker run -it --rm -v ~/.aws:/home/prowler/.aws prowlercloud/prowler aws --services s3 ec2

Azure scan:

docker run -it --rm -v ~/.azure:/home/prowler/.azure prowlercloud/prowler azure --services storage compute

Python Installation

pip install prowler

prowler aws --services iam ec2 s3

Common Use Cases

1. Compliance Auditing

CIS AWS benchmark:

prowler aws --compliance cis_v1.5_aws

NIST framework:

prowler aws --compliance aws_foundational_security_standard

2. Continuous Monitoring

JSON output for SIEM integration:

prowler aws --output-formats json --output-directory /var/log/security/

ASFF format for Security Hub:

prowler aws --security-hub --output-formats aws-security-finding-format

3. Multi-Account Assessment

Using AWS Organizations:

prowler aws --organizations-role ProwlerRole

Specific accounts:

prowler aws --role arn:aws:iam::ACCOUNT:role/ProwlerRole

Integration Tips

CI/CD Pipeline Integration

GitHub Actions:

- name: Run Prowler Security Scan

  uses: prowler-cloud/prowler@main

  with:

    command: aws --services s3 iam --severity critical high

    post-to-security-hub: true

Jenkins:

stage('Security Scan') {

    steps {

        sh 'prowler aws --output-formats json --quiet'

        publishHTML([allowMissing: false,

                     alwaysLinkToLastBuild: true,

                     keepAll: true,

                     reportDir: 'output',

                     reportFiles: '*.html'])

    }

}

SIEM Integration

Splunk HEC:

prowler aws --output-formats json | curl -k "https://splunk:8088/services/collector" -H "Authorization: Splunk YOUR_TOKEN" -d @-

ELK Stack:

filebeat.inputs:

- type: log

  paths:

    - "/var/log/prowler/*.json"

  json.keys_under_root: true

Common Issues and Solutions

Permission Errors

Issue: "Access denied" errors during scans

Solution: Use ReadOnlyAccess + SecurityAudit managed policies:

{

    "Version": "2012-10-17",

    "Statement": [

        {

            "Effect": "Allow",

            "Action": [

                "support:Describe*",

                "trustedadvisor:Describe*"

            ],

            "Resource": "*"

        }

    ]

}

Rate Limiting

Issue: API throttling with large environments

Solution: Use service filtering and parallel execution:

Split by services:

prowler aws --services iam --parallel

prowler aws --services s3 --parallel

Use rate limiting:

prowler aws --aws-retries 3 --sleep-seconds 1

Memory Issues

Issue: Out of memory errors on large scans

Solution: Filter by region and services:

Region-specific scans:

prowler aws --regions us-east-1 us-west-2

Critical services only:

prowler aws --services iam s3 ec2 --severity critical

Recent GitHub Issues (Sept 2025)

Active Development Areas

• GitHub Security Checks: New checks for organization settings (#8660-8663)

• Multi-account UI: Enhanced scanning interface (#8537)

• Azure China Support: Regional compliance fixes (#8425)

• M365 Compliance: CISA baseline integration (#8381)

• Token Management: 24-hour expiration fixes (#8170)

Known Bugs to Monitor

• Timestamp Issues: Report timestamps may be incorrect (#8591)

• False Positives: OpenSearch accessibility checks (#8566)

• Firehose Encryption: False positive findings (#8564)

• Docker Compose: EC2 connection issues (#8369)

Best Practices

1. Baseline Establishment

Initial comprehensive scan:

prowler aws --compliance cis_v1.5_aws --output-formats html json

Store baseline:

mv output/prowler-output-* /security/baselines/$(date +%Y%m%d)/

2. Regular Monitoring

Daily critical checks:

0 2 * * * prowler aws --severity critical --quiet --output-formats json

Weekly full scan:

0 1 * * 0 prowler aws --compliance cis_v1.5_aws

3. Alert Thresholds

Fail pipeline on critical findings:

prowler aws --severity critical

if [ $? -ne 0 ]; then

    echo "Critical security issues found"

    exit 1

fi

4. Custom Checks

Create custom checks in prowler/providers/aws/services/custom/:

from prowler.lib.check.models import Check, Check_Report_AWS

class custom_s3_encryption(Check):

    def execute(self):

        findings = []

        for bucket in s3_client.buckets:

            if not bucket.encryption:

                report = Check_Report_AWS(self.metadata())

                report.resource_id = bucket.name

                report.status = "FAIL"

                findings.append(report)

        return findings

Support Resources

• GitHub: https://github.com/prowler-cloud/prowler

• Documentation: https://docs.prowler.pro

• Slack Community: Join via GitHub issue #4124

• Commercial Support: https://prowler.pro

Next Steps

1. Start Small: Begin with single-service scans (IAM, S3)

2. Automate: Integrate into CI/CD pipelines

3. Customize: Add organization-specific checks

4. Scale: Implement multi-account scanning

5. Monitor: Set up continuous compliance monitoring

For Loki Labs implementations, coordinate with the SOC team for SIEM integration and establish baseline security postures for all client environments.