What Is Microsegmentation?

Rich Selvidge on July 18, 2024

The threat landscape has changed dramatically, but legacy network security strategies haven’t kept pace. Perimeter-based defenses like firewalls were sufficient when networks were static, and threats primarily came from outside the network.

However, modern IT environments are highly dynamic and distributed, with workloads frequently migrating between data centers and clouds. Meanwhile, insider threats and ransomware have become equally dangerous adversaries.

Researchers estimate that insider threats play a role in the majority of data breaches. According to Verizon, 85% of breaches involved a human element, with insider threats among the top attack patterns.

And IBM found that insider threat breaches were the most expensive on average, costing $250 per stolen record.

Fortunately, there is a modern approach to network security that can effectively address the threats posed by fluid IT environments and insider attacks: Microsegmentation.

This represents the future of network defense by fundamentally changing how networks are architected and secured.

Microsegmentation Explained

Microsegmentation is a network security strategy that divides a network into smaller, isolated segments to enhance security.

By implementing microsegmentation, organizations can apply specific security policies to each segment, ensuring more granular control over network traffic.

The key benefits of microsegmentation include reduced attack surface, enhanced security posture, and the ability to limit lateral movement of potential threats.

Microsegmentation is a well-established principle in network security.

However, the practical implementation of this strategy has historically been challenging.

The deployment of microsegmentation a serious commitment of time, manpower, and financial resources.

Types Of Microsegmentation

Micro-Segmentation can be applied in different ways depending on use case and environment:

Application Microsegmentation

Application microsegmentation isolates individual applications into separate zones with granular security policies specific to each one. This prevents lateral movement between applications if one is compromised.

Key benefits include:

Limits blast radius of exploits to a single application.
Applies context-aware rules tailored to each application’s needs.
Reduces complexity vs. sweeping network-level rules.

Network Microsegmentation

Network microsegmentation divides a network into isolated subnets or VLANs. If exploited, an attack’s impact is confined to one subnet.

Drawbacks vs. application segmentation include:

More coarse-grained approach.
Can still allow lateral movement within a subnet.
Doesn’t account for differences between applications.

Container Microsegmentation

Container microsegmentation treats each container as a distinct segment with its own security perimeter.

This prevents threats from breaking out of one compromised container into others.

Key benefits include:

Aligns with ephemeral nature of containers.
Better granularity than subnet-level segmentation.
Limits damage from exploits due to container isolation.

User Microsegmentation

User microsegmentation divides users into segments with authorized access to data and applications.

This restricts access to only approved resources based on identity.

The main advantages of user microsegmentation include:

Applies identity-based policies tailored to user roles,
Prevents access to sensitive data by unauthorized users,
Limits insider threats since users can only access designated resources,

Why Microsegmentation Is Important

The traditional approach to network defenses, often likened to a moat around a castle, is outdated and insufficient.

In this analogy, the moat represents the security measures taken to protect the digital information (the castle).

Once an adversary breaches the moat, it’s often too late, making attacks like ransomware highly effective at the employee level.

A single click on a malicious link can allow the attacker to move laterally across the network.

Microsegmentation, on the other hand, places a moat around every endpoint susceptible to a cyber attack, including servers, workstations, and IoT devices.

This approach significantly hinders the popular attack paths used by threat actors, making it less effective and more costly for them.

For example, when a threat actor targets the billing department of a healthcare organization as part of a ransomware attack, they’re hoping to use that as an entry point to compromise the rest of the network.

If the organization has implemented microsegementation across its network, the damage is confined to the employee’s device who clicked on the malicious link.

Learn More: How Microsegementation Prevents Ransomware Attacks

As a result, the organization can swiftly contain and resolve the threat preventing the ransomware from spreading. This ensures patient safety and avoids compliance violations and fees

Summary: Microsegmentation enhances digital defense by creating individual barriers around each network endpoint, countering the vulnerabilities of traditional security models. As modern IT landscapes evolve with cloud integration and rapid DevOps changes, microsegmentation ensures granular, tailored security, aligning with the zero trust model and effectively reducing breach impacts.

Limitations With The Traditional Approach

1. Network Segmentation

Traditional network segmentation often results in coarse-grained zones, which means that a single zone may contain multiple workloads with different trust and risk levels.

This lack of granularity can make it challenging to apply appropriate security measures tailored to each workload’s specific needs.

Learn More: Microsegmentation Vs Network Segementation: What’s Better?

Even if an organization has segmented its network, lateral movement between these segments is still possible once the perimeter has been breached.

This allows attackers to explore and potentially compromise more parts of the network.

There’s also a notable absence of workload-level policies that govern the east-west traffic between segments.

Once inside a segment, malicious actors can often communicate freely with other systems within that segment.

2. Rise Of Complex And Dynamic IT Environments

The increasing adoption of cloud services and the move towards hybrid infrastructures have made traditional network perimeters more porous and harder to defend.

Workloads frequently migrate between different environments, adding to the complexity of maintaining consistent security postures.

The growth of DevOps practices means that IT environments are changing more rapidly than ever, with new applications being deployed and existing ones updated at a fast pace.

This fluid connectivity can introduce new vulnerabilities if not managed correctly.

3. Aligning With Zero Trust Security Models

Zero trust security models emphasize the need to verify every entity trying to access resources, regardless of its location (inside or outside the network).

This means enforcing granular access controls for every workload.

Learn More: Why Microsegmentation Is A Core Component Of Zero Trust

Under a zero trust model, no asset is trusted by default. Communication is restricted to only what’s necessary, minimizing the potential for unauthorized access.

A core principle of zero trust is to always assume that threats exist inside the network. This proactive stance ensures that even if a threat actor gains access, their ability to cause harm is limited.

In response to these challenges, microsegmentation offers a more refined approach. It shifts the focus from broad network boundaries to individual workloads, allowing for tailored security policies for each.

This not only reduces the potential impact of a breach (the “blast radius”) but also shrinks the overall attack surface, providing robust security even in the face of increasing IT complexity.

Summary: Traditional network segmentation often lacks granularity, leading to challenges in applying specific security measures for different workloads and allowing potential lateral movement by attackers within segments. The rise of dynamic IT environments, driven by cloud adoption and rapid DevOps practices, complicates consistent security postures, especially as zero trust security models emphasize granular access controls and assume internal threats. In contrast, microsegmentation focuses on individual workloads, enabling tailored security policies that reduce the impact of breaches and offer robust security amidst growing IT complexity.

Microsegmentation Use Cases

1. Segmenting Payment Processing Systems

Isolating Payment Applications: Microsegmentation allows for the strict isolation of payment applications from other non-essential systems. This ensures that any potential breach in unrelated systems doesn’t compromise the integrity of the payment application.
Protecting Point of Sale (POS) Terminals: By segmenting POS terminals, each terminal operates within its own secure enclave. This reduces the risk of a compromised terminal affecting others or accessing the broader network.
Limiting Access to Payment Data: Microsegmentation ensures that only authorized personnel and systems have access to payment data. This minimizes the risk of internal threats and data leaks.
Enhancing Compliance Measures: Regulatory standards, such as PCI DSS, mandate strict controls over payment data. Microsegmentation aids in meeting these requirements by providing granular control over data access and flow.
Rapid Threat Containment: In the event of a security incident, microsegmentation allows for the quick isolation of affected systems. This prevents the spread of malicious activity and aids in faster incident resolution.

2. Preventing Ransomware From Spreading

Granular Traffic Control: Microsegmentation provides the ability to control traffic at a granular level, ensuring that only legitimate communication paths are allowed. This prevents ransomware from communicating with its command and control servers or spreading laterally within the network.
Isolating Infected Systems: In the event a system is compromised, microsegmentation can quickly isolate the affected system, preventing the ransomware from propagating to other parts of the network and limiting its impact.
Enhanced Monitoring and Detection: With microsegmentation, unusual traffic patterns, such as those indicative of ransomware activity, can be more easily detected. This allows for faster response times and immediate containment of threats.
Protecting Critical Assets: By segmenting critical assets and data from the rest of the network, microsegmentation ensures that even if ransomware enters the network, it cannot easily access or encrypt vital data, preserving business continuity.
Limiting User Access: Microsegmentation can be used to enforce strict user access controls, ensuring that users can only access what they need. This reduces the potential entry points for ransomware and ensures that if a user’s system is compromised, the ransomware’s reach is limited.

Learn More: How Microsegementation Prevents Ransomware Attacks

3. OT, ICS, And SCADA Networks

Enhanced Protection for Critical Infrastructure: OT (Operational Technology), ICS (Industrial Control Systems), and SCADA (Supervisory Control and Data Acquisition) networks control vital processes in industries like energy, manufacturing, and utilities. Microsegmentation ensures that these critical systems are isolated from non-essential systems, reducing the risk of cyberattacks that could disrupt essential services.
Limiting Lateral Movement: In the event of a breach, microsegmentation prevents attackers from moving laterally within the network. This is crucial for OT, ICS, and SCADA systems where unauthorized access to one component can have cascading effects on the entire operation.
Segmented Access Control: Given the sensitive nature of OT and ICS operations, microsegmentation can enforce role-based access controls, ensuring that only authorized personnel can interact with these systems, thereby reducing the risk of both external and internal threats.
Safeguarding Legacy Systems: Many OT, ICS, and SCADA systems run on legacy software that may not be regularly updated or patched. Microsegmentation provides an added layer of security, ensuring that these older systems are shielded from potential vulnerabilities present in other parts of the network.
Real-time Monitoring and Anomaly Detection: Microsegmentation allows for granular monitoring of network traffic within OT, ICS, and SCADA environments. This enables real-time detection of any anomalies or unauthorized activities, ensuring swift response to potential threats.

4. Isolating Customer Data Environments

Data Privacy and Compliance: By segmenting customer data environments, microsegmentation ensures that sensitive customer information remains isolated from other parts of the network. This not only protects data privacy but also aids in meeting regulatory compliance standards like GDPR and CCPA.a
Minimizing Breach Impact: In the event of a security incident, having customer data environments segmented ensures that a breach in one segment doesn’t compromise data in other areas, thereby limiting the overall impact and potential damage.
Tailored Security Protocols: Different types of customer data may require varied security measures. Microsegmentation allows for the application of specific security protocols tailored to the nature and sensitivity of the data within each segmented environment.
Preventing Unauthorized Access: With microsegmentation, access to customer data environments can be strictly controlled based on roles and responsibilities. This ensures that only authorized personnel can access specific data sets, reducing the risk of internal threats and data leaks.
Enhanced Monitoring and Alerting: By isolating customer data environments, microsegmentation facilitates more focused monitoring of data access patterns. Any unusual or unauthorized activity can be quickly detected and alerted, ensuring rapid response to potential threats.

5. Securing Admin Access To Databases

Role-Based Access Control: Microsegmentation allows for the implementation of strict role-based access controls for databases. By doing so, only administrators with the necessary credentials can access specific parts of the database, ensuring that sensitive data remains secure and inaccessible to unauthorized users.
Limiting Surface Area for Attacks: By segmenting administrative access, the potential entry points for malicious actors are reduced. Even if other parts of the network are compromised, the segmented database remains shielded from unauthorized access.
Real-time Monitoring of Admin Activities: With microsegmentation, all administrative activities on the database can be closely monitored. This ensures that any unusual or potentially harmful actions are detected immediately, allowing for swift intervention.
Enhanced Security for Remote Access: In scenarios where administrators need remote access to databases, microsegmentation can be used to create secure, isolated channels for such access, ensuring that potential vulnerabilities associated with remote connections are mitigated.

Top Challenges of Microsegmentation (And How to Overcome Them)

Complexity In Large Environments

The sheer scale of larger environments introduces a myriad of variables, complicating the task of maintaining consistent security measures across the board.

To combat this, experts recommend automating policy generation based on application metadata, ensuring a uniform security stance.

Additionally, given the multitude of applications and workloads, predicting the most effective security policies can be a complex endeavor. Machine learning comes to the rescue here, offering tailored policy recommendations for each application.

However, a fine line exists between over-restriction, which can impede operations and lax rules that leave vulnerabilities exposed.

It’s imperative to validate each rule with precision, ensuring a balanced approach that safeguards operations without compromising security.

Learn More: How To Implement Microsegmentation

Ongoing Policy Management

One of the primary reasons is the frequent disconnect between development and security. These two critical domains often operate in isolation, leading to potential security blind spots.

To bridge this gap, it’s essential to embed security policies directly within the Continuous Integration/Continuous Deployment (CI/CD) pipelines, ensuring that security isn’t an afterthought but a foundational component.

Furthermore, as networks and threat landscapes are in a state of constant flux, relying on outdated rules can be a recipe for disaster.

You must periodically reassess and update these rules to stay ahead of emerging threats. Lastly, with so many tools and platforms in play, achieving a clear, overarching view of policy management can be elusive.

Centralized management platforms are the answer, offering a unified lens through which policies can be effectively overseen and adjusted.

Potential Performance Impacts

One of the most pressing concerns is that security policies, while designed to protect, can inadvertently cripple network performance.

Overly restrictive rules have the potential to slow down or even block essential business processes. To mitigate this, it’s crucial to rigorously evaluate these policies in pre-production settings, fine-tuning them for a balance between security and performance.

Another stumbling block is the use of physical firewalls, which can introduce bottlenecks due to hardware limitations. The solution lies in leveraging virtual appliances that offer the same level of security but with greater fluidity in network traffic.

Moreover, business operations often necessitate specific data flows that can be disrupted by overzealous security policies. Therefore, you need to optimize these policies to facilitate essential business flows without compromising on security.

Cross-Platform Inconsistencies

The complexity introduced by hybrid environments often come with varying security measures, leading to potential inconsistencies that can compromise the network’s integrity.

To address this, it’s essential to gravitate towards solutions that offer unified policy control, ensuring a consistent security posture across these hybrid landscapes.

Another layer of complexity arises from infrastructure differences. Policies designed for one infrastructure might not seamlessly apply to another, risking their effectiveness.

The remedy here is to abstract the policy from its underlying infrastructure, ensuring its consistent application regardless of the platform. Furthermore, not all platforms natively support micro-segmentation, creating potential security vulnerabilities.

To bridge these security gaps, integrating SDN plugins or leveraging network virtualization becomes indispensable, ensuring airtight security across the entire network.

Skillset Requirements

At its core, microsegmentation demands a specialized set of knowledge. However, not every network or security engineer is well-versed in its nuances, leading to potential vulnerabilities or misconfigurations.

The solution? A concerted effort to cross-train both network and security professionals, ensuring they’re equipped with the principles and practices of micro-segmentation.

Moreover, the actual implementation of micro-segmentation is no walk in the park. Without the requisite expertise, the process can become drawn-out and riddled with errors.

To navigate this, many organizations are turning to professional services, aiming to both expedite and refine their microsegmentation rollouts.

Additionally, while vendor-specific tools offer a promising avenue to simplify micro-segmentation adoption, they come with their challenges.

Each vendor presents unique tools and best practices. Navigating this landscape requires a commitment to leveraging these tools effectively and adhering to best practices, ensuring a seamless and secure microsegmentation deployment.

Summary: Ongoing policy management is crucial, especially with the frequent disconnect between development and security, necessitating the integration of security policies into CI/CD pipelines and the use of centralized management platforms. Addressing potential performance impacts, cross-platform inconsistencies, and skillset requirements involves a combination of pre-production evaluations, unified policy controls, cross-training, and leveraging vendor-specific tools for effective microsegmentation deployment.