Cloud Security Best Practices

It seems like nearly every organization wants some digital presence in the cloud today.  This trend toward cloud migration continues to gain momentum, propelled by its appealing advantages, including scalability, flexibility, and cost efficiency. However, the nature of cloud security significantly differs from traditional on-prem security, forcing IT and cybersecurity leaders to rethink their security strategies to ensure they have the right mix of tools, controls, personnel, and strategies to establish a comprehensive cloud security posture.

Why Is Cloud Security Important?

Organizations are increasingly relying on cloud environments that, in turn, expose them to new types of threats. It's vital to understand these risks, given the distinct nature of cloud computing compared to traditional IT setups. The cloud's scalability and accessibility, while beneficial, also open doors for cybercriminals. Key to this endeavor is understanding the shared responsibility model of cloud security in which the cloud provider secures the infrastructure, but the organization is responsible for protecting its data within the cloud. This requires a strategic approach to identity and access management, data encryption, threat detection, and incident response, tailored to the cloud environment. Due to the virtual separation between your operations and the cloud infrastructure, it's crucial to implement continuous monitoring and conduct regular security assessments. This proactive approach helps promptly identify and mitigate risks and prevent data breaches.

Cloud Service Models

Cloud data security best practices cover a range of processes that include control over people, applications and infrastructure. Which best practices for cloud security are important for your security strategy depends in part on the cloud service model you use. Cloud computing services are grouped into three types listed here with some examples:

• Infrastructure as a service (IaaS) — Azure, AWS, virtual data centers
• Platform as a service (PaaS) — Redhat Openshift, Oracle Cloud
• Software as a service (SaaS) — Microsoft 365, Salesforce

Each model addresses a different set of business requirements and demands different security measures.

IaaS

Within the Infrastructure as a Service (IaaS) framework, the customer assumes the system administrator's duties. This position enables them to allocate network-accessible storage, oversee processing capabilities, deploy and manage applications alongside operating systems. While IaaS admins have some discretion in choosing network components like the host firewall, direct management or control over the underlying cloud infrastructure remains outside their jurisdiction.

For IaaS, your security best practices include, but not limited to:

• Data governance
• Client and endpoint protection
• Identity and access management
• Application-level controls
• Network controls
• Security testing

PaaS

In the PaaS model, you leverage the cloud vendor's platform and resources for the development, testing, deployment, and management of applications. Unlike the IaaS model, it does not grant you the ability to manage or control the underlying cloud infrastructure, such as networks, servers, operating systems, or storage. However, you can deploy your applications to the PaaS infrastructure using programming languages and tools that the PaaS provider supports. 

In the PaaS model, your security tasks extend to, but are not confined to:

• Data governance
• Client and endpoint protection
• Identity and access management
• Application-level controls
• Security testing

SaaS

Software as a Service (SaaS) delivers applications over the internet, enabling users to access and utilize software through web browsers on various devices. This service model empowers users to engage in a range of tasks, from data analysis to collaborative projects, without the need for installing or maintaining software locally. While users can customize certain aspects of the application's settings to fit individual or team needs, the control over all underlying cloud-based infrastructure remains with the SaaS provider. This setup eases the IT burden for users by shifting the management and maintenance responsibilities to the provider.

For SaaS, your security responsibilities include, but not limited to:

• Data governance
• Client and endpoint protection
• Identity and access management

Cloud Deployment Models

The realm of cloud computing presents a variety of models, each with unique advantages tailored to serve specific requirements and strategic goals of organizations. Whether it's the extensive reach and flexibility of public clouds or the enhanced security measures of private clouds, the deployment model outlines the interaction between the cloud provider and the consumer. How you utilize various cloud computing services is influenced by your business's specific traits and the nature of the data you possess. The primary cloud deployment models are as follows:

• Private Cloud – Provisioned for use by a single organization, it offers enhanced security and control. Hosted either on-premises or by a third party provider, it provides the flexibility and scalability of cloud technology, while maintaining strict access and data privacy, tailored to meet specific business needs.
• Public Cloud – Designed for multi-tenant use, its services and infrastructure are hosted off-site by a cloud provider, allowing shared access amongst multiple organizations (tenants). It offers scalability, reliability, and cost-effectiveness, with resources available on-demand. Ideal for a wide range of applications, it's commonly used for web-based email, online office applications, and storage.
• Hybrid cloud — Combines public and private cloud infrastructures to allow data and applications to be shared between them. This model offers businesses flexibility, scalability, and optimized security by keeping sensitive data on-premises while leveraging the public cloud for scalable resources and innovation, facilitating a balanced approach to cloud computing.

Steps to Implement the Best Practices

Embarking on the journey to implement best practices and technologies within an organization is a strategic move toward enhancing efficiency, security, and overall performance. Below we will outline the steps necessary to adopt and integrate them effectively. By following these steps, you can position your organization to meet its objectives more successfully and maintain a competitive edge in your industry.

Risk Management in the Cloud

Before embracing a cloud service, consumers must evaluate potential risks linked to adopting cloud solutions for specific information systems and formulate strategies for mitigating these risks. A thorough risk assessment should identify:

• Essential components for securing your cloud environment
• Controls that need to be implemented internally
• Controls that fall under the cloud provider's jurisdiction

Cloud Security Best Practices at the Infrastructure Level

The entire hardware infrastructure should be controlled, secured, and hardened. This begins with configuration auditing to ensure the cloud environment is configured according to your organization’s policies or relevant compliance standards. Implement regular audits to check for signs of misconfiguration. Improper configuration settings can put you at serious risk of data loss. To ensure configuration checks are performed regularly, automate them with a monitoring solution, and promptly investigate and remediate any suspicious changes in your cloud environment.

You should also take the following steps in relation to incident prevention, detection, and response:

• External Attack Defense: Implement advanced malware protection across IaaS platforms and assess perimeter vulnerabilities to shield against DDoS attacks targeting public cloud interfaces.
• Intrusion Detection and Prevention: For IaaS, deploy intrusion detection systems at the user, network, and database levels. In PaaS and SaaS models, this responsibility shifts to the provider.
• Traffic Monitoring: Monitor for spikes in traffic, as these could indicate potential security incidents.

Cloud Security Best Practices at the Application Level

The most important aspect of application-level security is ensuring that vulnerabilities within the application itself are identified and remediated. This includes enforcing strong authentication and authorization controls to manage access, encrypting data at rest and in transit to prevent unauthorized access, and regularly updating and patching the application to address security flaws. Some critical areas to focus on include the following:

Permissions Management

• Implement Least Privilege Access - Assign only the necessary permissions for each user to perform their job functions.
• Regular Entitlement Reviews and Rights Revocation - Periodically assess and adjust permissions, removing any that are no longer needed.
• Unauthorized Changes Monitoring - Keep a close watch for any unauthorized changes to group memberships, especially those that alter administrative privileges, as well as permissions assigned directly to users bypassing group memberships.

Authentication

• Make multi-factor authentication (MFA) mandatory - MFA significantly enhances security by requiring multiple forms of verification, making unauthorized access much harder for potential attackers.
• Monitor login activities: - Investigate spikes in failed logins to identify potentially compromised accounts, setting up alerts for login attempts from multiple endpoints, numerous failed logins by any account in a short timeframe, and a high number of login failures within a specified period.

Activity Monitoring

Utilize User Behavioral Analytics (UBA) to identify unusual activities such as shifts in a user's behavior or access patterns that might potential security threats or malicious traffic. Other suggestions include the following:

• Consistently monitor and document user activities to establish normal behavior baselines.
• Spot users exhibiting actions that stray from their individual or group baseline.
• Keep an eye out for unauthorized or external file sharing.

Cloud Security Best Practices at the Data Level

Data must be protected regardless of its location and that includes the cloud. By implementing these best practices below, organizations can ensure their data's confidentiality, integrity, and availability, thereby fortifying their cloud data security posture and protecting their most valuable assets.

Data Discovery and Classification

• Identify and classify your data — Data discovery and classification is used to evaluate and categorize your data based on its importance and sensitivity. You can then utilize the insights gained to focus your data protection strategies, establishing suitable security controls and policies. Automating this process can help achieve consistent and precise outcomes.
• Strategize Cloud Data Governance - Determine which data will reside in the cloud and outline its governance strategy to protect all sensitive data. It's critical to ensure the protection of sensitive data within the cloud. Certain information might require on-premises storage to adhere to stringent security protocols or compliance requirements.

Data Access Standards

• Implement Data Access Management - Conduct frequent audits of access privileges, particularly for your organization’s most sensitive data and remove any unnecessary permissions. Apply appropriate access controls based on the data type.
• Restrict Data Sharing - Enforce rules to mitigate risks of accidental public exposure or unauthorized external data sharing.
• Monitor File Downloads - Monitor for unusual download activities and prohibit downloads to unsecured devices. Require device security verification prior to allowing downloads. Utilize automated monitoring throughout the IT environment to track users who download, alter, or share cloud-based data.

Data Protection

• Automated Data Remediation - Adopt a system capable of automatically transferring at-risk data to a secure quarantine zone to mitigate vulnerability.
• Refine Data Erasure Practices - Eliminate redundant or obsolete data following NIST and ISO recommendations. NIST and ISO guidelines recommend using cryptographic erasure, an industry-standard technique that renders data unreadable by discarding its encryption keys. Deletions must be auditable.
• Encrypt Data in Transit and at Rest - Prioritize encryption for all data before uploading it to the cloud. Maintain strict control over encryption keys using comprehensive key management practices to secure them properly.
• Develop a Robust Data Recovery Strategy - Regularly back up data and establish a thoroughly tested recovery procedure to efficiently address accidental and intentional data loss.

Best Practices for Secure Cloud Service Management 

Managing business relationships aims to facilitate efficient exchanges between the cloud provider and the consumer, with a primary emphasis on addressing security requirements and concerns. A primary area of focus should be on contracts and service level agreements (SLAs). The contract serves as your primary assurance for service quality and remediation efforts. Thoroughly review the agreement's terms and conditions to ensure they align with your organization's security standards. Ask for clarity on anything that may seem ambiguous such as whether clients are allowed to audit the provider's compliance.

A critical aspect of the contract is defining responsibility and ownership of the data stored in the cloud. Legal ownership can be ambiguous and unclear. Prior to finalizing a contract, strive to negotiate any terms you find unacceptable. If certain terms cannot be altered, evaluate the associated risks. If acceptable, consider strategies like encryption or monitoring to mitigate risks. Otherwise, seeking an alternative provider that meets your specific requirements may be necessary.

Define Shared Responsibilities

Establish a clear understanding of cybersecurity responsibilities between you and the provider by addressing key points such as:

• The extent of the provider's liability.
• The provider's policies for data storage and deletion.
• The security measures in place to protect your data.
• The audit and control measures implemented by the provider and those required on your end.
• Strategies for ensuring data confidentiality.

Ensure Regulatory Compliance

Selecting a cloud service provider doesn't absolve your organization from the responsibility of regulatory compliance. The burden remains on you to create and maintain cloud-based applications and services that comply with relevant regulations continuously.

A reputable cloud provider adheres to recognized standards and commits to transparency and accountability. Providers demonstrating this commitment often hold certifications like SAS 70 Type II or ISO 27001. A reputable provider should provide comprehensive access to documentation and reports relevant to compliance assessments and consent to independent audits conducted in accordance with established standards. The provider is responsible for maintaining certifications and should notify consumers of any status changes.

Develop an Incident Response and Disaster Recovery Plan

Creating an incident response plan with your cloud service provider involves the two of you defining shared security responsibilities, establishing communication protocols, and identifying critical assets and risks. The plan should outline the specific services the cloud provider will offer in response to an incident. Tailor response procedures to address potential incidents, integrating cloud-specific tools for enhanced detection and response. Regular training and simulations ensure preparedness, while ongoing reviews of the plan adapt to the evolving cloud environment and threat landscape. This collaborative approach ensures a unified and effective response to incidents, safeguarding operations and data in the cloud.

Navigating the nuances of cloud security is essential in today's technology-driven landscape. To ensure the safety and integrity of your cloud data and the continuous availability of cloud services, it is important to implement continuous monitoring for early threat detection. Regular comprehensive testing along with extra evaluations after significant architectural changes will bolster your security defenses. By adopting these proactive measures, organizations can maintain a robust security posture, safeguarding their critical assets against the evolving threats in the cloud environment.