Cloud Security Assessment: How to Audit Your AWS/Azure/GCP Environment

Cloud misconfigurations are now the leading cause of data breaches, responsible for 15% of all incidents according to IBM. An exposed S3 bucket, an overly permissive IAM role, or an unencrypted database snapshot can expose millions of records. This guide walks you through a systematic cloud security assessment.

Why Cloud Security Assessments Are Critical

The shared responsibility model means your cloud provider secures the infrastructure, but you are responsible for securing everything you build on top of it. AWS will not stop you from making an S3 bucket public, granting AdministratorAccess to every IAM user, or leaving your RDS instance accessible from the internet. These misconfigurations are your responsibility, and they are the most common attack vector in cloud breaches.

According to Gartner, through 2025, 99% of cloud security failures are the customer's fault. The complexity of cloud services — AWS alone has over 200 services, each with its own security configurations — makes it nearly impossible to maintain a secure posture without systematic assessment. A cloud security assessment identifies these misconfigurations before attackers exploit them.

Cloud Security Assessment Checklist

1. Identity and Access Management (IAM)

IAM misconfigurations are the most dangerous because they can give attackers the keys to everything:

• Enforce MFA on all IAM users, especially those with console access
• Eliminate or restrict the root account — do not use it for daily operations
• Apply least-privilege policies — no *:* or AdministratorAccess for service accounts
• Rotate access keys every 90 days and remove unused keys
• Use IAM roles (with temporary credentials) instead of long-lived access keys
• Implement identity federation (SSO) for human access
• Review IAM policies for overly permissive resource wildcards
• Enable AWS IAM Access Analyzer, Azure AD PIM, or GCP IAM Recommender

2. Storage Security

• Verify no S3 buckets, Azure Blob containers, or GCS buckets have public access
• Enable server-side encryption on all storage (SSE-S3, SSE-KMS, or customer-managed keys)
• Enable versioning and MFA delete on critical buckets
• Review bucket policies for overly permissive principals ("Principal": "*")
• Enable access logging on all storage containing sensitive data
• Block public access at the account level (S3 Block Public Access)
• Scan for exposed credentials in stored files using tools like truffleHog or git-secrets

3. Network Security

• Review security groups for overly permissive inbound rules (especially 0.0.0.0/0 on SSH/RDP/database ports)
• Implement VPC flow logs for all VPCs and subnets
• Use private subnets for databases and internal services
• Deploy NAT gateways for outbound internet access from private subnets
• Enable AWS GuardDuty, Azure Defender, or GCP Security Command Center
• Review NACLs for unnecessary allowed traffic
• Verify that load balancers terminate TLS with valid certificates — check with our SSL Checker

4. Compute Security

• Use hardened AMIs/images with unnecessary services removed
• Keep all instances patched and updated
• Disable SSH password authentication — use key-based access only
• Restrict instance metadata service (IMDS) to IMDSv2 (prevents SSRF-based credential theft)
• Enable instance encryption (EBS encryption, Azure Disk Encryption)
• Review auto-scaling configurations for security group inheritance
• Scan container images for vulnerabilities before deployment (Trivy, Snyk, ECR scanning)

5. Database Security

• Ensure databases are not publicly accessible (no public endpoints)
• Enable encryption at rest and in transit for all database services
• Implement database authentication with IAM where supported
• Enable automated backups with encryption and test restoration procedures
• Review database parameter groups for insecure settings
• Enable audit logging for all database access
• Use Secrets Manager or Parameter Store for database credentials — never hardcode them. Validate with our ENV Validator

6. Logging and Monitoring

• Enable CloudTrail (AWS), Activity Log (Azure), or Cloud Audit Logs (GCP) in all regions
• Store logs in a separate, restricted account or bucket with immutable retention
• Enable VPC Flow Logs, DNS query logging, and load balancer access logs
• Set up alerts for high-risk events: root account usage, security group changes, IAM policy modifications, failed authentication attempts
• Retain logs for at least 12 months (compliance requirement for most frameworks)
• Integrate cloud logs with your SIEM for centralized analysis

7. Secrets Management

• Store all credentials in a secrets manager (AWS Secrets Manager, Azure Key Vault, GCP Secret Manager)
• Rotate secrets automatically on a defined schedule
• Never commit credentials to source code — use our API Key Security Guide
• Audit secret access patterns for unauthorized usage
• Encrypt secrets at rest using customer-managed keys

Cloud Security Assessment Tools

Open-Source Tools

• Prowler: AWS and Azure security best practices assessment. Covers CIS benchmarks, PCI DSS, HIPAA, and GDPR. Free, actively maintained, 300+ checks.
• ScoutSuite: Multi-cloud security auditing for AWS, Azure, GCP, and Oracle Cloud. Generates HTML reports with findings categorized by severity.
• CloudSploit: Open-source cloud security scanning for AWS, Azure, GCP, and Oracle. API-driven with CI/CD integration.
• Checkov: Infrastructure-as-code scanner for Terraform, CloudFormation, Kubernetes, and ARM templates. Catches misconfigurations before deployment.

Commercial Tools

• Wiz: Agentless cloud security platform with risk-based prioritization. Connects directly to cloud APIs for comprehensive visibility.
• Orca Security: SideScanning technology for deep workload visibility without agents. Covers VMs, containers, serverless, and Kubernetes.
• Prisma Cloud (Palo Alto): Comprehensive CNAPP covering CSPM, CWPP, CIEM, and code security. Enterprise-grade with broad cloud coverage.

The CIS Benchmarks

The Center for Internet Security (CIS) publishes detailed security benchmarks for each major cloud provider. These benchmarks provide specific, actionable configuration recommendations organized into levels:

• Level 1: Essential security settings that can be implemented without significant operational impact
• Level 2: Advanced settings that may limit functionality but provide defense-in-depth

Using CIS benchmarks as your assessment baseline ensures comprehensive coverage and aligns with compliance requirements. Tools like Prowler and ScoutSuite can automatically evaluate your environment against CIS benchmarks and flag deviations.

Common Cloud Security Mistakes

1. Publicly accessible storage: S3 buckets, Azure Blob containers, and GCS buckets with public read access containing sensitive data. Always enable account-level public access blocks.
2. Overprivileged IAM policies: Granting AdministratorAccess or *:* permissions to applications that only need access to a single S3 bucket. Use the principle of least privilege with specific resource ARNs.
3. Unencrypted data: Databases, EBS volumes, and snapshots without encryption enabled. Enable encryption by default at the account level.
4. Missing logging: Disabling CloudTrail or not enabling it in all regions. Attackers specifically target regions where logging is disabled.
5. Hardcoded credentials: API keys, database passwords, and tokens committed to source code or stored in environment variables on instances. Use secrets managers exclusively.
6. Security group sprawl: Accumulating hundreds of security groups with rules nobody understands. Audit and consolidate regularly.

Frequently Asked Questions

How often should we conduct cloud security assessments?

Run automated assessments continuously or at least weekly using tools like Prowler or ScoutSuite. Conduct comprehensive manual reviews quarterly. Trigger additional assessments after major architecture changes, new service adoptions, or compliance audits. The SecureBin Exposure Checker can be used for ad-hoc external checks of your cloud-hosted applications.

Should we use a CSPM tool or manual assessments?

Both. Cloud Security Posture Management (CSPM) tools provide continuous automated monitoring that catches drift and new misconfigurations in real-time. Manual assessments provide depth that automated tools miss — reviewing architecture decisions, evaluating custom applications, and testing complex permission chains. Start with open-source tools (Prowler, ScoutSuite) for immediate value, then consider commercial CSPM as your environment grows.

How do we handle multi-cloud security assessments?

Multi-cloud environments multiply complexity because each provider has different security models, terminology, and configuration options. Use tools that support all your cloud providers (ScoutSuite, Wiz, Prisma Cloud) to maintain a unified view. Standardize security policies across providers where possible, but recognize that implementation will differ. Assign cloud-specific security specialists or invest in multi-cloud training for your team.

The Bottom Line

Cloud security is fundamentally a configuration problem. The services themselves are secure — it is how you configure and use them that creates vulnerabilities. A systematic cloud security assessment covering IAM, storage, networking, compute, databases, logging, and secrets management catches the misconfigurations that lead to breaches. Start with automated tools for breadth, supplement with manual reviews for depth, and run assessments continuously rather than annually. In the cloud, your security posture changes every time someone modifies a resource — your assessment program must keep pace.

Related tools: Exposure Checker, SSL Checker, DNS Lookup, ENV Validator, Subnet Calculator, and 70+ more free tools.