What is a Cloud Access Security Broker (CASB)? 

Cloud adoption has grown rapidly as companies pivot to support the remote workforce and take advantage of the various benefits of cloud computing. However, along with these benefits, the cloud also brings significant cloud security challenges. One critical solution designed to address the unique challenges organizations face as they adopt cloud services is the cloud access security broker (CASB), a security policy enforcement point that sits between cloud applications and users. 

Let’s take a closer look at the challenges that a CASB can address: 

  • Shadow IT: SaaS applications and other cloud services are easy for employees to configure and use. As a result, corporate data may be stored and processed by unmanaged and unsecured cloud applications. CASB provides insight into what cloud applications employees are using, and can manage unauthorized access.
  • Lack of Visibility: Cloud visibility can be difficult since companies lack full control over their infrastructure stack and may be using dozens of SaaS applications and other resources. As a result, security incidents in the cloud may go undetected or are more difficult to investigate and remediate. CASB offers enhanced cloud visibility by providing insight into all usage of an organization’s cloud assets.
  • Dissolving Perimeters: Traditionally, organizations could manage access to their data by deploying security at the perimeter. Cloud resources sit outside the corporate perimeter, making it easier for attackers to gain access and breach sensitive data. CASB enables organizations to monitor and control access to cloud-based data, reducing the risk of data breaches.

The Four Core Pillars of CASB

#1. Visibility

CASBs act as an intermediary between cloud applications, services, and their users. This provides the visibility required to understand cloud application usage. CASB solutions offer full visibility into user activity, access to corporate data, and potential threats to an organization’s data and applications.

In addition to providing insight into potential cloud security incidents, CASB can also help to identify shadow IT and the use of unsanctioned applications in the cloud. While these applications can be benign, IT teams require visibility to ensure that they are properly secured and to maintain control over corporate data and compliance with applicable regulations.

#2. Compliance

Cloud environments commonly contain sensitive data that is protected under regulations such as HIPAA, PCI-DSS, and GDPR. These regulations have various requirements that enterprises need to comply with, such as:

  • Access Management: Data privacy laws mandate that organizations control access to customers’ sensitive data. CASB solutions have full visibility into access requests for cloud data, enabling them to prevent unauthorized access to protected data.
  • Data Residency: The GDPR and similar regulations restrict cross-border data flows, which can be difficult to detect and block in the cloud. CASB enhances cloud visibility, enabling an organization to prevent access to protected data from outside of approved jurisdictions.
  • Compliance Audits: Companies must be able to provide audit trails and reports to demonstrate that they have appropriately controlled access to protected data. CASB’s detailed logging provides the information needed to demonstrate compliance with various regulations.

As companies are subject to an expanding number of regulations, compliance becomes more complex. CASB enables centralized compliance management and the visibility required to prove compliance and generate required reports.

#3. Data Security

Cloud environments are designed to make data easily accessible and shareable. While this is great for usability, it can create security challenges.

CASB enables organizations to prevent unauthorized access to sensitive corporate data by enforcing corporate cybersecurity policies. With visibility into cloud access requests, organizations can enforce access controls and implement DLP policies that restrict downloads and sharing of sensitive data. Additionally, CASB can support data security best practices such as encryption of data at rest and in transit.

#4. Threat Protection

In addition to acting as a policy enforcement point, CASB can also protect against threats to the organization. CASB solutions can identify and block ransomware and other types of malware as well as other threats to the business.

CASB has access to a rich dataset regarding access attempts for corporate cloud assets. CASB incorporates user and entity behavior analytics (UEBA) capabilities, which can be used to identify anomalies that point to compromised accounts and insider threats.

CASB Deployment Architectures

CASB solutions can be deployed using a few different architectures, including:

  • API-based: API-based CASB solutions connect directly to cloud services for visibility and control. This provides out-of-band inspection and policy enforcement, which can help to improve application performance and the CASB’s scalability. Additionally, API-based solutions may have the potential to retroactively take action if a threat is detected after the fact.
  • Proxy-based: Proxy-based CASB is deployed in-line between users and the cloud. This enables real-time enforcement of an organization’s security policies.
  • Multi-mode: Multi-mode CASB combines the API and proxy-based deployment architectures to offer the most comprehensive coverage. Multi-mode architectures can both offer real-time policy enforcement and the ability to perform retroactive actions.

The right choice for an organization’s cloud architecture depends on its use cases and security requirements. API-based CASB offers out-of-band protection, which is more scalable and has better performance than in-line. Proxy-based protection, on the other hand, can block malicious requests before they reach the target system, offering real-time protection against threats.

CASB’s Role in SASE Frameworks

Secure access service edge (SASE) converges network and security functions into a unified cloud service. SASE is composed of software-defined WAN (SD-WAN) and security service edge (SSE).

CASB is a key component of SASE and SSE. It integrates with secure web gateways (SWGs), zero trust network access (ZTNA), and other SASE technologies to implement granular access controls and security for cloud resources.

Evaluation Criteria for CASB Solutions

CASB is an integral part of a cloud security architecture. Some of the key components and functions to look for in a CASB solution include the following:

  • Comprehensive Coverage: Companies often use various Software as a Service (SaaS), Infrastructure as a Service (IaaS), and Platform as a Service (PaaS) solutions across multiple cloud environments. A CASB solution should offer integrated coverage for all of an organization’s cloud solutions.
  • Deep Policy Enforcement: CASB solutions extend enterprise security policies to the cloud. CASB solutions should be able to implement an organization’s DLP and other security policies.
  • Threat Detection and Response: CASB plays a crucial role in managing access to cloud solutions and protecting them from attack. A solution should be able to identify potential threats and help organizations to respond to them.
  • Ease of Deployment and Management: Many security teams struggle to manage an array of security solutions. CASB solutions should be easy to deploy and manage as part of an integrated security architecture.
  • Integration with Existing Security Architecture: CASB is one component of an organization’s cloud and overall security architecture. CASB solutions should integrate with other security functions — such as SWG and ZTNA — to enhance cloud security.

The Future of CASB

CASB acts as an important security policy enforcement for cloud environments, which means it needs to evolve with an organization’s cloud security needs. Some potential future trends for CASB solutions include:

  • App Specialization: CASB can only enforce security policies that have already been defined. With the rise of AI, CASB may offer the ability to intuitively define and enforce policies for custom apps and machine learning workloads.
  • Security Integration: Companies are moving away from point security products to more usable and efficient security platforms. In the cloud, this means that CASB will likely be increasingly integrated into cloud security platforms and SASE frameworks.
  • Automated Enforcement: AI offers the ability to inspect security data and identify anomalies and potential threats. AI integration into CASB solutions will likely enhance its ability to detect threats and policy violations.

Cato Networks and CASB

Cato SASE Cloud combines CASB with other crucial cloud security functions in a converged, cloud-native solution. Learn more about Cato’s CASB, as well as the benefits of converged cloud security with SASE.