CAASM vs EASM: Managing Attack Surfaces

Cyber Asset Attack Surface Management (CAASM) and External Attack Surface Management (EASM) are two common techniques for managing attack surfaces of an organization. Here’s a breakdown of both concepts, their strengths and weaknesses, and guidance on when to use one approach over the other.

What is CAASM (Cyber Asset Attack Surface Management)?

CAASM focuses on the comprehensive visibility and management of all cyber assets within an organization’s environment, including on-premises, cloud, and hybrid infrastructures. It aims to identify and assess vulnerabilities, misconfigurations, and potential attack vectors associated with these assets. CAASM tools provide insights into how these assets can be exploited and help organizations prioritize their security efforts.

What is EASM (External Attack Surface Management)?

EASM specifically concentrates on the external-facing components of an organization’s digital presence. This includes assets exposed to the internet, such as websites, applications, APIs, and cloud services. EASM aims to identify and analyze the attack surface from an external perspective, uncovering vulnerabilities and risks that can be exploited by attackers attempting to breach the organization from the outside.

CAASM: Strengths and Weaknesses
Strengths	Weaknesses
Comprehensive Asset Visibility: CAASM provides a holistic view of all cyber assets, including those that may not be directly exposed to the internet but are still critical to security.	Complexity: The cloud environment can be highly complex, making it challenging to accurately map and manage assets.
Internal Context: It offers insights into how assets interact and the potential attack paths within the organization, allowing for better risk assessment and remediation.	Limited Scope: Some CAASM solutions may not cover all aspects of the cloud environment, potentially leaving some areas vulnerable.
Integrated Vulnerability Management: By encompassing all assets, CAASM enables organizations to prioritize vulnerabilities based on the overall risk they pose to the business.	Evolving Threat Landscape: As cyber threats evolve, CAASM tools may struggle to keep up with the latest attack vectors and tactics.

EASM: Strengths and Weaknesses
Strengths	Weaknesses
External Threat Focus: EASM specializes in identifying and managing risks associated with an organization’s public-facing assets, making it particularly relevant for understanding external threats.	Limited Internal Visibility: EASM does not provide insights into internal assets, which may overlook critical vulnerabilities and threats that could be exploited internally.
Proactive Risk Management: By monitoring external attack surfaces, organizations can identify potential vulnerabilities before they are exploited by attackers.	Potential Overlook of Non-Internet Exposed Assets: Many risks come from assets that aren’t directly exposed to the internet, and EASM might miss these altogether.
Simplified Scope: EASM often has a narrower focus, which can make it easier to implement and manage compared to a comprehensive CAASM solution.	Reactive Nature: EASM may often focus on identifying existing vulnerabilities rather than providing a comprehensive strategy for ongoing risk management.

When to Use CAASM vs. EASM

When to Use CAASM

CAASM’s approach tends to shine in a Diverse Asset Environment, meaning if your organization has a complex IT landscape that includes a mix of on-premises and cloud assets, CAASM is beneficial for gaining visibility and managing risks across the entire environment.

They are also great for Internal Threat Mitigation: Organizations focused on addressing internal risks, such as insider threats or lateral movement within networks, can benefit from CAASM’s comprehensive asset visibility.

Regulatory Compliance Needs: If compliance mandates require a detailed understanding of all cyber assets, CAASM can help meet those requirements.

When to Use EASM

EASMs are focused on External-Facing Priorities: If your organization is particularly concerned about external threats, such as cyberattacks targeting public-facing applications and services, EASM is the right approach.

By focusing on scope up-front, EASMs can be easier to implement if your team has Limited Resources: EASM’s focused scope can make it easier to implement and manage while still providing valuable insights into external risks.

Because of their external focus, EASMs are great for companies who need to worry about their Public Image and Reputation: Organizations that rely heavily on their online presence and customer trust may prioritize EASM to safeguard against vulnerabilities that could lead to breaches or data exposure.

Where do Non-Human Identities (NHIs) fit in?

What are NHIs?

Non-human identities (a term that encompasses over 1000 types of digital communication including service accounts, cryptographic keys, tokens, APIs, certificates, and more) play a critical role in cloud-native applications.  Cloud applications are composed of microservices and workloads that interact with each other to perform and deliver a service to an end user.  The identities of these interactions as well as the related permissions associated with these identities are referred to as NHIs.

Is there an EASM and CAASM for NHIs?

While EASM and CAASM technologies reduce the attack surface for assets and from external vectors, they focus on physical assets and external threats.  A similar approach can be taken for NHIs to further restrict and reduce exposure to compromise.

Securing non-human identities (NHIs) necessitates a thorough understanding of their historical context and full lifecycle. NHIs can be utilized in various ways across different environments, leading to diverse scopes and functions. To secure NHIs, it’s essential to focus on several key activities: enhancing their creation through measures like segregation of duties, scope restrictions, and storage requirements; managing their use by establishing baseline behaviors, detecting anomalies, monitoring activities, and responding in real-time; and safely terminating or rotating identities when they are no longer necessary. Achieving these objectives effectively requires a dedicated platform for non-human identities that integrates information from multiple sources, such as Entro Security.

Conclusion

In conclusion, both CAASM and EASM play important roles in a comprehensive security strategy. CAASM offers a holistic view of an organization’s cyber assets, while EASM provides targeted insights into external threats. Depending on your organization’s specific needs, risk profile, and resources, you may choose one approach over the other—or ideally, implement both to achieve a balanced security posture that addresses both internal and external risks effectively.