Multi Cloud Security: 10 Critical Best Practices

What is Multi Cloud Security?

A multi cloud strategy allows organizations to deploy workloads across multiple cloud platforms, including both public clouds, such as AWS, Azure, and Google Cloud Platform, and private clouds. This provides much more flexibility than working with only one cloud platform, allows organizations to better manage costs and avoid vendor lock in, and improves resiliency. According to research from Oracle, 98% of organizations are using at least two clouds and 31% use four or more.

However, the high complexity of multi cloud deployments also increases the attack surface and the risk of cyberattacks, raising new cloud security concerns. Multi cloud security requires a holistic approach that addresses diverse security vulnerabilities and establishes consistent security controls across multiple, heterogeneous environments.

We’ll cover 10 critical best practices for multi cloud security – key considerations that can help improve multi cloud workload security in daily operations.

In this article, you will learn:

• Why Use a Multi Cloud Strategy?
• Multi-Cloud Security Challenges
• 10 Security Best Practices for Multi Cloud Environments
• Multi Cloud Security with Aqua

Why Use a Multi Cloud Strategy?

The multi cloud strategy allows businesses to choose from a variety of cloud services from different providers. This can have several important benefits:

• Specialization—some cloud platforms may be more suitable for specific tasks or workloads. For example, one cloud provider may provide lower cost storage, more powerful compute instances, or specialized services for analytics or machine learning.
• Cost and financial leverage—operating across multiple cloud providers lets organizations leverage the services with the most attractive cost, and use their multi cloud deployment as a leverage when negotiating with cloud providers.
• Disaster recovery—while cloud providers provide extensive high availability options across data centers and geographical regions, outages can happen. Deploying the same service across multiple clouds provides outstanding resilience and more extensive options for disaster recovery and business continuity. 

Multi-Cloud Security Challenges

Misconfigured Cloud Configurations or Architecture

Misconfigured cloud resources are among the leading causes of data breaches in a multi cloud environment. When settings or access controls are improperly configured, it can inadvertently expose sensitive data to the internet or unauthorized users. 

For example, an S3 bucket on AWS left public without proper access restrictions can lead to a significant data breach. Similarly, misconfigurations in networking settings, such as overly permissive firewall rules or default credentials not being changed, can provide attackers with easy access to cloud resources. 

Technical teams must meticulously review and continuously monitor cloud configurations to ensure they align with security best practices. Tools like Cloud Security Posture Management (CSPM) can help automate the detection and remediation of such misconfigurations.

Insufficient Visibility

In a multi cloud environment, maintaining visibility into resource utilization, operational performance, and security posture across different platforms is challenging. Without comprehensive visibility, organizations can’t effectively identify vulnerabilities or monitor for suspicious activities. This lack of insight can leave blind spots for attackers to exploit. 

For example, if an organization has separate tools to monitor traffic to and from virtual machines in AWS and Azure, it may be difficult to identify attacks that span across both clouds. Using centralized logging and monitoring solutions that aggregate data from all cloud environments is crucial. These solutions should offer features like anomaly detection and real-time alerts to help security teams respond, regardless which cloud system an attacker targets

Larger Attack Surface

The complexity and diversity of multi cloud environments inherently expand the attack surface. Each cloud provider has its unique set of services, interfaces, and security controls, complicating the security management. 

Each cloud is only as strong as its weakest security link. For example, an API endpoint exposed to the internet in Google Cloud could expose that environment to attack, while a misconfigured identity and access management (IAM) policy in AWS could lead to unauthorized access of AWS resources. Organizations need to conduct regular security assessments and penetration testing across all cloud environments to identify and mitigate potential vulnerabilities, ensuring that security policies are uniformly applied.

Shared Responsibility Models

The shared responsibility model in cloud computing delineates the security obligations of the cloud provider and the customer. However, this model can have subtle differences between different cloud providers, leading to confusion and potential security gaps. 

Misunderstanding these responsibilities can lead to inadequate security controls or, conversely, redundant security measures. Organizations must clearly understand and adhere to their responsibilities in each cloud environment, supplementing cloud provider controls with their own security measures, such as end-to-end encryption and access control management.

Data Governance and Compliance

Managing data governance and compliance becomes more complex in a multi cloud setup. Each cloud provider may have different compliance certifications and data protection standards, and data may be subject to varying legal and regulatory requirements based on its location. 

An organization using AWS for processing personal data of EU citizens, for instance, must ensure GDPR compliance, whereas data stored in Azure for healthcare applications in the US must comply with HIPAA. This is further complicated by differences in compliance details between these two clouds.

Ensuring consistent data governance policies and compliance across multiple clouds requires a robust data classification system and compliance monitoring tools. These tools help in mapping out where sensitive data resides across clouds and automating compliance reporting and audits.

10 Security Best Practices for Multi Cloud Environments

When designing your multi cloud architecture, the following best practices will help you secure your infrastructure and workloads:

1. Authentication and authorization—find a framework that can support the different authentication models used by different cloud providers, but lets you define accounts, roles and policies in a centralized manner. It is important for authentication and authorization to be decoupled from any particular cloud service or provider.
2. Upgrades and patching—vulnerabilities and remediations may be different for each cloud provider, even for the same type of infrastructure or workload. Automate software upgrades and patches, ensuring that upgrades are sensitive to the workload, the infrastructure it is currently running on, and its dependencies.
3. Component hardening—applications and infrastructure components must be hardened according to the relevant security best practices. This involves closing unsecured ports, removing unnecessary software, securing APIs and web interfaces, and following the principle of least privilege for access to users and services.
4. Monitoring and visibility—when operating on one cloud, you could rely on the basic security tools offered from that cloud provider. However, in a multi cloud environment, you must have a tool that supports multiple clouds and enables visibility of the entire environment. A holistic view of systems across the multi cloud is essential for detecting, investigating, and responding to cyber threats.
5. Multi cloud storage—classify data that will be stored on the multi cloud, and ensure that sensitive data is assigned to the most secure storage resources. Plan geographical distribution of data according to your compliance obligations. Implement data loss prevention (DLP) solutions that can identify data loss or exfiltration across multiple clouds.
6. Synchronize policies—if you use multiple clouds for availability, you need to ensure you use the same security settings in all your clouds. You can use automated tools to synchronize policies and settings between providers. These tools should create security policies based on generic definitions that apply to all providers.
7. Tailor security policies to services—each workload or application running on the multi cloud should have its own security profile and appropriate security policies. These policies should be based on the intended use of the workload, whether it is business critical, the sensitivity of the data, and compliance obligations.
8. Automate security—it is common to automate processes on public clouds, and you should extend this principle to security. Adopt a DevSecOps mentality in which every process occurring on your cloud infrastructure should take security into account, and adopt the relevant security practices. For example, every new VM or container deployed on any cloud should undergo the relevant security scans.
9. Consolidate monitoring—establish a security monitoring strategy that consolidates logs, alerts and events from all cloud providers in one place. Beyond monitoring, implement automation that is triggered by alerts, and implements the relevant remediations on any cloud with no human intervention. 
10. Automate compliance across clouds—each cloud platform has different compliance certifications and features. You may also be running different workloads with different compliance obligations on each cloud. Use an automated platform to audit compliance across clouds and generate reports showing violations and suggested remediations.

Multi Cloud Security with Aqua

With Aqua, organizations can leverage the capabilities of cloud workload protection with cloud infrastructure best practices for full-stack security. Aqua is the only pure play cloud native security company to converge the capabilities of a cloud workload protection platform (CWPP) and cloud security posture management (CSPM) in one complete solution.

Aqua security provides security controls for cloud migration and multi-cloud deployments with persistent controls that follow workloads wherever they run.

The Aqua Platform provides security controls for containers and serverless functions throughout their lifecycle, and supports all container orchestrators, public and private cloud platforms including AWS, Azure, GCP, IBM Cloud, Oracle Cloud, and VMware. It ensures uniform security and compliance enforcement across all these environments.

In a multi cloud or hybrid environment, Aqua can help with:

• Cross-environment segmentation—Aqua provides a container firewall that segments workloads within the same environment or across clouds, preventing attacks from spreading, the spread of attacks, without interfering with cloud deployments.
• Multi-tenancy control and security—Aqua can manage multiple team deployments or customer tenancies from a central console. It maintains separation of data and access, ensuring complete isolation between tenants.
• Scanning images and functions—Aqua scans container images and serverless functions for known vulnerabilities, embedded secrets, OSS licensing issues, malware, and configuration issues before they are deployed.
• Protect serverless workloads—Aqua protects serverless environments such as AWS Fargate and Azure Container Instances, from a single console with consistent policy enforcement.
• Infrastructure Security —  Aqua Cloud Security Posture Management (CSPM) provides scanning, monitoring, and remediation of configuration issues in public cloud accounts. 
• Multi-Cloud Visibility—Aqua CSPM continually audits cloud accounts for security risks and misconfigurations across hundreds of configuration settings and compliance best practices to enable consistent, unified multi-cloud security.
• Rapid Remediation of Misconfigurations—Aqua provides self-securing capabilities to ensure cloud accounts do not drift out of compliance and delivers detailed, actionable advice and alerts, or choose automatic remediation of misconfigurations with granular control over chosen fixes.
• Enterprise Scale—Aqua supports hundreds of cloud accounts using an extensible plugin architecture. It is also API/Cloud Dev friendly, uses SSO with SAML 2.0 and integrates with many popular productivity tools.