Cloud Security

Securing Multi-Cloud Environments

Best practices for maintaining security consistency across AWS, Azure, and GCP deployments.

March 8, 2025•6 mins read•By Claire Bennett, Cloud Security Architect

Modern multi-cloud architectures combine services from AWS, Azure, and Google Cloud

As organizations increasingly adopt multi-cloud strategies (87% according to Flexera's 2025 report), security teams face unprecedented challenges managing disparate environments. Our research shows that 68% of breaches in multi-cloud setups stem from configuration errors and identity management gaps rather than sophisticated attacks.

The Multi-Cloud Security Challenge

Managing security across AWS, Azure, and Google Cloud requires addressing three core complexities:

Inconsistent Policies

Each cloud provider implements security controls differently - AWS IAM vs Azure RBAC vs Google Cloud IAM.

Identity Sprawl

The average enterprise has 17,000+ cloud identities with 34% being overprivileged (2025 CrowdStrike data).

Visibility Gaps

47% of organizations cannot track data flows between cloud platforms in real-time.

Complex data flows in multi-cloud environments require specialized monitoring

"During a recent assessment, we discovered a Fortune 500 company had 1,200 dormant storage buckets across three clouds containing sensitive data, all accessible via legacy service accounts. This blind spot existed because their tools only monitored their primary cloud."

- BTM Cloud Security Team

Proven Security Framework

1. Unified Identity Fabric

Implement cloud-agnostic identity management:

# Example Terraform for multi-cloud identity sync
module "azure_ad_connector" {
  source  = "terraform-aws-modules/iam/aws//modules/iam-assumable-role"
  providers = {
    aws = aws.primary
    azuread = azuread.prod
  }
  
  trusted_role_arns = [
    "arn:aws:iam::ACCOUNT_ID:role/AzureAD-SSO",
    "roles/cloudidentity.googleapis.com/gcp-sync"
  ]
}

This infrastructure-as-code approach ensures consistent identity policies across clouds

2. Policy-as-Code Enforcement

Tools like Open Policy Agent (OPA) can standardize rules:

Prevent public storage buckets across AWS S3, Azure Blob, and Google Cloud Storage
Enforce encryption-in-transit regardless of cloud provider
Auto-remediate violations within 15 minutes of detection

Automated policy enforcement reduces configuration drift

3. Cross-Cloud Monitoring

Essential capabilities for visibility:

Key Monitoring Requirements

Unified log collection from all cloud providers
Normalized alert taxonomy (e.g., "DataExfiltration" vs "SuspiciousBlobAccess")
Cross-cloud correlation of user activities

Implementation Roadmap

Phase	Activities	Success Metrics
1. Assessment	Cloud asset inventory Identity mapping	100% assets cataloged
2. Hardening	Policy-as-code implementation Secrets management	90%+ policy compliance
3. Monitoring	SIEM integration Threat detection rules	<30m mean detection time

Pro Tip: The 3-2-1 Backup Rule for Multi-Cloud

Maintain 3 copies of critical data on 2 different cloud platforms with 1 offline backup. This protects against both cloud provider outages and ransomware attacks targeting cloud storage.