September 4, 2024
Episode 11
Architecting Zero Trust for the Cloud
Author: Brian "BP" Panarello
In our previous exploration of the evolving cybersecurity landscape, we established the limitations of traditional perimeter-based defenses and underscored the necessity of embracing a Zero Trust security model. We introduced the concept of Cloud Native Access Points (CNAPs) as crucial components in implementing Zero Trust, particularly within cloud environments.
As organizations increasingly migrate their workloads and data to the cloud, ensuring the security of those environments takes on paramount importance. This is where the CNAP emerges as a critical component of a modern, Zero Trust security posture.
Let's delve deeper into the design and deployment considerations for a CNAP, examining how this security architecture can be leveraged to safeguard sensitive data and applications in real-world scenarios, addressing the unique security challenges of cloud environments.
Reference Design Requirements & Capabilities
The Department of Defense (DoD) has recognized the critical need for robust cloud cybersecurity and has developed a comprehensive Cloud Native Access Point Reference Design (CNAP RD). This document provides a detailed framework and best practices for designing, deploying, and operating CNAPs within the context of DoD's cybersecurity posture.
The CNAP RD outlines four primary capabilities that a CNAP should possess:
Authenticated and Authorized Entities: The CNAP must ensure that all users and entities attempting to access cloud resources are authenticated and authorized based on robust identity verification mechanisms and granular access control policies.
Authorized Ingress: All inbound network traffic to the cloud environment must be inspected and authorized by the CNAP, ensuring that only legitimate requests are permitted to reach sensitive resources.
Authorized Egress: The CNAP must also scrutinize outbound network traffic, preventing data exfiltration and ensuring that data leaving the cloud environment complies with relevant security policies and regulations.
Security Monitoring and Compliance Enforcement: The CNAP plays a crucial role in continuous security monitoring, threat detection, and compliance enforcement. It should provide centralized logging, security information and event management (SIEM) integration, and automated compliance reporting capabilities.
Nebula CNAP Design: A Practical Implementation
To illustrate the practical implementation of a CNAP, let's examine the US Space Force Nebula Controlled Services Environment CNAP design, which leverages a combination of commercial off-the-shelf (COTS) technologies and cloud-native services to provide comprehensive cloud security within a Zero Trust framework.
But First, A Little Background
Nebula is a United States Space Force Controlled Services Environment that provides cloud infrastructure and financial operations for Assured Access to Space launch Operations (Space Launch Deltas 30/45, also known as Western and Eastern Launch Ranges, respectively). Based in AWS GovCloud, the Nebula environment provides access to AWS first-party services and a handful of other tools to facilitate the migration of Space Force applications to a Cloud Smart platform. Nebula also eases the burden for customers’ ATO efforts by providing over 40% full-control inheritance, and up to 92% of controls either partially or fully inheritable (e.g., hybrid controls).
Nebula was designed out of a need to provide a collaborative cloud environment for both DoD and non-DoD mission partners (think SpaceX, ULA) to plan and execute launch operations. Many of the engineers from these partnerships do not have GFE equipment, don’t have access to the typical DoD networks, and might not even have a CAC for their identity. Because of this, the Nebula does not require a CAC for authentication/authorization – rather a CAC is an option.
The Nebula CNAP architecture encompasses the following key components:
Okta Identity Services: Okta acts as the primary identity provider (IdP), enabling strong authentication mechanisms such as multi-factor authentication (MFA) and single sign-on (SSO). It enforces granular access control policies based on user roles and attributes.
Zscaler Private Access (ZPA): ZPA provides Zero Trust Network Access (ZTNA) capabilities, ensuring that users are granted secure access only to the specific applications and resources they are authorized to use.
Palo Alto Next-Generation Firewall (NGFW): The Palo Alto NGFW serves as a robust network security perimeter, providing deep packet inspection, intrusion prevention, and application control to block malicious traffic and enforce security policies.
Elasticsearch: Elasticsearch acts as the central logging and security information and event management (SIEM) platform, aggregating and analyzing security logs from various CNAP components to facilitate threat detection, incident response, and compliance reporting.
Applied Zero Trust: Extending Identity-Based Security Throughout the Cloud
The true power of a CNAP, exemplified by the Nebula design, lies in its ability to extend Zero Trust principles beyond simply securing access to the cloud environment. It achieves this by leveraging identity as the cornerstone for adjudicating access to resources throughout the cloud ecosystem.
This means that every interaction with cloud resources, whether initiated by a user, an application, or even another cloud service, is subject to the same rigorous verification and authorization process enforced by the CNAP. This continuous, identity-driven security posture ensures that:
Access is Granted on a Need-to-Know Basis: Users and entities are only granted access to the specific resources required to perform their authorized tasks, minimizing the potential attack surface and limiting the damage in case of a breach.
Contextual Factors Inform Access Decisions: CNAPs leverage contextual information, such as user location, device security posture, and time of day, to make more informed access control decisions. For example, a user attempting to access sensitive data from an unrecognized device or location might trigger additional verification steps or be denied access altogether.
Security Policies are Consistently Enforced: By integrating with cloud service provider (CSP) native security controls, such as AWS Organizations, AWS Identity and Access Management (IAM), and AWS IAM Access Policies, CNAPs can extend their policy enforcement capabilities across the entire cloud infrastructure.
The Nebula CNAP design, by integrating seamlessly with these native cloud security controls, embodies this concept of "extended Zero Trust." It effectively leverages identity as the common thread, weaving a tapestry of security across the cloud environment and ensuring that every interaction is authenticated, authorized, and aligned with the organization's security posture.
The dynamic and distributed nature of cloud environments necessitates a security model that moves beyond static perimeters and embraces the fluidity and diversity of users, devices, and applications. The CNAP, with its ability to enforce identity-based access control at every point of interaction, provides this essential capability. Thus, organizations can achieve a more granular, context-aware, and adaptable security posture, mitigating risks and safeguarding their valuable assets in the cloud.
As organizations increasingly adopt hybrid and multi-cloud strategies, the complexity of managing security across these diverse environments will continue to grow. CNAPs, with their ability to provide centralized policy enforcement, identity management, and threat visibility, will play an increasingly vital role in securing these complex deployments. The future of cloud security lies in embracing a Zero Trust approach, and CNAPs stand as essential tools in realizing this vision.
However, establishing a secure architecture is only one facet of a robust cybersecurity posture. Maintaining continuous vigilance and possessing the ability to respond swiftly and effectively to security events are equally critical. In our next installment, we will delve into the realm of continuous monitoring and automated response, exploring how these capabilities augment the effectiveness of Zero Trust security models and empower organizations to proactively mitigate evolving cyber threats.
Nebula Controlled Services Environment
CNAP Reference Design
https://dodcio.defense.gov/Portals/0/Documents/Library/CNAP_RefDesign_v1.0.pdf
EO 14028 “Improving the Nation’s Cybersecurity”
Google BeyondCorp