What is Microsegmentation?
Microsegmentation is a cloud network security practice in which architects separate a network into segments that are guarded by granular network security controls. Microsegmentation prevents attackers from moving laterally throughout your network and makes it more difficult for them to exfiltrate data.
As a cornerstone of zero trust cloud security, microsegmentation enables organizations to significantly reduce their attack surface by enforcing consistent security policies across distributed, ephemeral, and high-velocity cloud environments.
How Does Microsegmentation Help Cloud Security?
Microsegmentation is the key to consistent and enforceable single-, hybrid, or multicloud security.
Organizations are increasingly adopting hybrid or multicloud architectures to meet the growing demand for access to resources and services. However, the legacy security models that were designed for physical, on-premises environments do not provide enough protection for cloud environments.
Legacy security models were created to protect a physical network perimeter. In contrast, cloud workloads are distributed across geographical boundaries, regulatory frameworks, and heterogeneous environments. A cloud network doesn’t have one clear perimeter; instead, every cloud workload has a micro-perimeter that needs protection.
To protect thousands of perimeters across clouds and environments, cloud security teams are forced to design fragmented and complex security policies. The lack of visibility and ability to enforce these policies creates blind spots and vulnerabilities that threat actors are eager to exploit.
Microsegmentation mitigates these vulnerabilities by enforcing granular access control policies between workloads while improving compliance posture and providing contextual visibility.
However, implementing microsegmentation in the cloud is difficult. Native cloud constructs vary by cloud provider, and integrating them can be time-consuming, draining, and expensive.
How Can I Adopt a Cloud Microsegmentation Strategy?
Designing a microsegmentation strategy takes time, resources, and cross-team coordination. Here are five practical steps to design and implement an effective cloud microsegmentation strategy.
Step 1: Identify High-Value Assets
To begin, identify high-value information assets, such as resources and workloads, that are critical for your organization’s success.
Threat actors rely on low barriers to compromise. By implementing and enforcing least-privilege access control through microsegmentation, you can increase the barriers to compromise and decrease your attack surface. Microsegmentation also decreases the blast radius of an incident by limiting attackers’ ability to move laterally in your network.
Step 2: Implement Centralized Policy Governance
Second, implement a strategy for centralizing your security policies across your entire network. Pair this governance with contextual telemetry and data analytics to improve situational awareness, detection rates, and response times.
Step 3: Implement Distributed Policy Enforcement
Third, make sure you can enforce your security policies across your entire distributed network. This enforcement must extend beyond inter-VPC boundaries to include intra-VPC boundaries. Doing so reduces the risk of threat actors will gain a persistent foothold through additional attack vectors.
Once a threat actor compromises a target, their first objective is to evade defenses, escalate local privileges, and gain unauthorized access to local resources. Once this attack vector has been exhausted, their next goal is to expand their foothold by compromising other, easily accessible targets.
These targets are usually near the initial point of compromise in a cloud environment, often residing in the same VPCs and subnets. To mitigate this risk, you need host-level network access control – though that can make administration more complicated.
To effectively implement and enforce a “nanosegmentation” like this in a cloud environment, without creating unmanageable administrative complexity, use cloud native security group orchestration to enforce network segmentation at the endpoint.
Step 4: Seamless Security Ecosystem Integration
Develop a strategy to integrate your microsegmentation strategy with pre-existing security architecture solutions. This integration will prevent challenges like interoperability, vendor lock-in, and business disruption and maximize your business’s agility during the transition.
Step 5: Prevent, Detect, and Respond
After setting up your microsegmentation framework, determine an ongoing management system to maintain:
Visibility – Visibility into and continuous monitoring of cloud environments.
Telemetry – Insightful security analytics, such as traffic anomalies and threat intelligence, to make informed decisions about policy design, implementation, and enforcement.
Threat detection – Make sure you can quickly determine the origin and target of attacks and enforce granular security policies.
For more guidance on microsegmentation, see 4 Phases to Implementing Microsegmentation.
Summary
Microsegmentation is an essential part of zero trust cloud security because it enforces security policies consistently across your network, shutting down lateral movement and the kind of visibility gaps that attackers can exploit. The key to effective microsegmentation is centralized governance, distributed enforcement, and ongoing visibility. Having these in place will help your network on your journey to zero trust maturity and proactive, ongoing protection.
