What is CASB Security? Guide on Cloud Access Security Brokers in 2025

Back in 2006, Amazon launched Amazon Web Service - a service that allowed Amazon to rent computing resources to clients globally. 17 years later, Amazon enjoys more than 1 million active customers across 190 countries - a massive feat hard to replicate. 

However, in reality, not everything’s good in paradise. The company faces cyber threats every odd second, and despite implementing strong security protocols, a cyber-security firm identified over 6.5 terabytes of exposed information in May of 2022. 

This raises eyebrows and makes us think, is our data really secure? More significantly, how safe are our businesses’ valuable digital assets? 

The answers lie in Cloud Access Security Broker (CASB).

What is CASB Security?

A Cloud Access Security Broker (CASB) is a security policy enforcement point positioned between cloud service consumers and providers. It enforces enterprise security policies and provides visibility, compliance, data security, and threat protection when accessing cloud services.

In simpler terms, a CASB serves as an intermediary between users and cloud services. It not only monitors all activity but also enforces your organization's security policies. Think of CASB as a gatekeeper, allowing safe and compliant cloud access while denying any potentially risky activities or transactions.

CASBs are crucial in the current era of increasing cloud adoption and growing cybersecurity threats. They address the unique security challenges that arise from the use of cloud services, including the risk of data leakage, unauthorized access, and non-compliance with regulations.

Building blocks of CASB Security (Pillars of CASB)

The below pillars represent the core components necessary for any CASB solution:

1. Visibility:

CASBs provide visibility and control over both managed and unmanaged cloud services. They help identify "shadow IT," which includes undocumented systems and cloud services that may pose security risks. CASBs enable IT to monitor and govern access to activities and data within cloud services while allowing useful ones. This includes discovering all cloud services in use, reporting on cloud expenditure, and identifying redundant functions and costs.

2. Compliance:

CASBs ensure adherence to industry-specific compliance standards such as SOC 2, HIPAA, and GDPR. They help organizations meet regulatory requirements by implementing robust security controls crucial for healthcare, retail, and financial services. CASBs maintain compliance with these regulations, protecting against data breaches and avoiding penalties and fines.

3. Data Security:

CASBs prevent confidential data from leaving company-controlled systems and ensure data integrity. This is particularly important with the rise of AI tools, where employees might upload sensitive data. Technologies like access control and data loss prevention (DLP) are essential for securing sensitive data and preventing unauthorized transfers.

4. Threat Protection:

CASBs provide real-time scanning and remediation of threats across internal and external networks. They block external threats and attacks, stop data leaks, and prevent unauthorized access. Key technologies include anti-malware detection, sandboxing, packet inspection, URL filtering, and browser isolation, all of which help block cyber attacks and ensure comprehensive threat protection.

Key Use Cases of CASB Security

• Cloud Data Access Control
• Shadow IT Discovery
• Enforces Security Policies
• Data Loss Prevention
• Cloud Application Visibility
• Identity Protection
• Advanced Threat Detection and Protection
• Encryption and Tokenization
• Compliance Monitoring

1. Cloud Data Access Control

A CASB helps manage various aspects of cloud security such as identifying unauthorized cloud services (also known as Shadow IT), flagging potential risks associated with various cloud applications, and tracking user behavior to detect anomalies. For instance, if an employee starts downloading excessive amounts of data from a cloud service, the CASB could detect this unusual behavior and alert the administrators.

2. Shadow IT Discovery

CASB aids in identifying unsanctioned cloud applications used by employees (Shadow IT), allowing IT administrators to assess associated risks and manage cloud application usage appropriately.

3. Enforces Security Policies

One of the fundamental roles of a CASB is allowing administrators to enforce granular security policies across different cloud applications. This capability ensures that your organization's use of cloud services aligns with your internal security policies and regulatory requirements. For example, you can set policies to restrict access to sensitive data based on user roles, locations, or devices.

4. Data Loss Prevention

Cybersecurity threats are escalating, with more than 236.1 million attacks hitting servers globally each year. A CASB protects sensitive data from these threats in the organization's cloud environment, thereby helping to mitigate risks associated with data breaches and cyber-attacks. This protection includes features like encryption, tokenization, and data loss prevention (DLP).

By providing visibility into cloud application usage, enforcing security policies, and protecting sensitive data, a CASB plays an invaluable role in an organization's overall cybersecurity framework.

A Cloud Access Security Broker (CASB) is integral to any cloud security strategy due to its extensive capabilities. It facilitates visibility, data protection, threat detection, and policy enforcement, enabling organizations to confidently embrace cloud services while maintaining control over their data and ensuring compliance with industry standards. Let's delve into some of these capabilities in detail:

5. Cloud Application Visibility

A CASB grants organizations real-time visibility into cloud applications. It helps distinguish between sanctioned and unsanctioned (Shadow IT) cloud applications, giving IT administrators insights into cloud service usage and potential security risks.

6. Identity Protection

‍ CASB integrates with identity providers to enforce robust authentication methods, such as Multi-Factor Authentication (MFA) and Single Sign-On (SSO). This safeguard ensures that only authorized users can access cloud applications and data.

7. Advanced Threat Detection and Protection

CASB deploys sophisticated threat detection mechanisms to identify and neutralize various cloud-based threats, including malware, ransomware, phishing attempts, and other suspicious user activities. It alerts in real-time and responds to potential security breaches. For instance, if a user logs into Salesforce from Russia five minutes after logging into Office 365 from California, the CASB will detect this anomaly through a combination of detailed activity logs and User and Entity Behavior Analytics (UEBA).‍

8. Encryption and Tokenization

CASB incorporates encryption and tokenization capabilities to secure sensitive data at rest and in transit. Encryption ensures that intercepted data remains unreadable to unauthorized individuals. Tokenization replaces sensitive data with non-sensitive tokens, further enhancing data security. For example, Strac as a tokenization provider offers UI components that block the parent page from accessing sensitive data. Strac then tokenizes this data and returns the tokens to the UI app.

9. Compliance Monitoring

CASB supports organizations in meeting regulatory compliance requirements, ensuring that data stored and processed in the cloud aligns with industry-specific regulations such as GDPR, HIPAA, and CCPA. Many CASB solutions offer compliance reporting and auditing features, assisting organizations in adhering to these regulations.

By integrating these key capabilities, a CASB provides a holistic and flexible approach to cloud security, shielding organizations from emerging threats and mitigating risks associated with cloud-based services.

What security capabilities do CASBs offer?

CASBs provide a range of security capabilities designed to protect cloud environments. The key security capabilities offered by CASBs include:

• Identity Verification: It ensures that users are who they claim to be by verifying multiple identity factors, such as passwords or physical tokens. This multi-factor authentication helps prevent unauthorized access to cloud services.
• Access Control: CASBs enforce policies that determine user permissions based on roles, ensuring that sensitive data is only accessible to authorized personnel. They also help regulate what users can see and do within company-controlled applications. 
• Shadow IT Discovery: It identifies unauthorized systems and services internal employees use for business. This capability helps organizations uncover and manage unapproved cloud applications that may introduce security risks.
• Data Loss Prevention (DLP): It prevents data leaks by ensuring sensitive information does not leave company-owned platforms. DLP technologies monitor and control data transfer, using encryption and tokenization to secure data.
• URL Filtering: CASBs also block access to malicious websites used by attackers for phishing or malware distribution. This interception prevents users from inadvertently accessing harmful sites that could compromise security.
• Packet Inspection: A CASB analyzes data packets entering or exiting the network for signs of malicious activity. This helps detect and block threats before they can harm the cloud environment.
• Sandboxing: You can run programs and code in an isolated environment to test for malicious behavior. This allows potentially harmful software to be analyzed safely without affecting the main network.
• Browser Isolation: This method executes users' browsers on a remote server instead of local devices. It protects devices from potentially malicious code that can run in web browsers, ensuring safer browsing experiences.
• Anti-Malware Detection: It also identifies and blocks malicious software through advanced techniques to detect malware and prevent threats from infecting cloud applications and data.

How Does Cloud Access Security Brokers Work?

CASB solutions operates through two primary deployment models: API-based and Proxy-based. Here's how you can implement each model,

API-based CASB

In the API-based model, the CASB integrates directly with the cloud service providers’ APIs, enabling it to monitor and control data and activities within the cloud applications. This model provides more visibility without rerouting traffic but requires cloud providers to expose their APIs for integration.

Here is how you can implement API-based CASB:

Step 1: Discovery and Inventory

The CASB discovers and inventories all cloud applications used across your organization. It differentiates between sanctioned and unsanctioned applications, providing administrators with a comprehensive view of all cloud services in use. 

Step 2: API Integration and Data Collection

The CASB integrates with the cloud service providers’ APIs. This integration allows it to access metadata, user activity logs, and other relevant information from cloud applications. It also collects data on user actions, file activities, login attempts, and security events within the cloud environment.

Step 3: Continuous Monitoring and Visibility

The CASB continually monitors user activities and real-time data within the cloud applications. This provides IT administrators with visibility into who is accessing what data, from where, and on what device.

Step 4: Data Loss Prevention and Policy Enforcement

The CASB can enforce on sensitive data within cloud applications. It also enforces encryption, access controls, and other security practices based on predefined rules and compliance requirements.

Step 5: Threat Detection and Response

CASB employs advanced threat detection mechanisms to identify and block cyber threats aimed at cloud applications. It can enforce encryption, access controls, and other security policies based on pre-defined rules and compliance requirements.

Step 6: Reporting and Compliance

API-based CASB generates comprehensive reports on cloud application usage, security events, policy violations, and compliance status. These reports are essential for compliance audits and improving cloud security practices. 

Proxy-based CASB

In the proxy-based CASB deployment model, CASB acts as an intermediary proxy between users and cloud services. All traffic passes through the CASB, enabling real-time inspection, data protection, and policy enforcement. The Proxy-based approach introduces some latency but provides robust security features. Here is how it works:

Step 1: Traffic Redirection

All user traffic to and from cloud applications is redirected through the CASB proxy. Users must authenticate with the CASB before accessing cloud resources, ensuring all cloud activities are routed through the security gateway. 

Step 2: Inspection and Policy Enforcement

CASB inspects all traffic passing through the proxy, scanning for potential threats and policy violations. It enforces security policies like data encryption, access controls, and DLP-based predefined rules. 

Step 3: Malware and Threat Detection

Proxy-based CASBs employ real-time malware and threat detection mechanisms to identify and block malicious content before it reaches the cloud applications or the end users. 

Step 4: Data Protection and Encryption

CASB can encrypt data before it leaves the organization’s network, ensuring that sensitive information remains protected throughout its journey to the cloud. 

Step 5: Access Control and Authentication

CASB enforces strong authentication mechanisms, such as multi-factor authentication (MFA) and single sign-on (SSO), to ensure that only authorized users can access cloud resources. 

Step 6: Monitoring and Reporting

The CASB continuously monitors cloud activities, generating logs and reports on user behavior, policy compliance, security incidents, and threat intelligence.

CASB’s ability to provide comprehensive visibility, control, data protection, and threat detection makes it a crucial component of modern cloud security strategies. 

Also read: How Strac protects sensitive data with tokenization

Essential CASB Features to Look For in 2024

Choosing the right CASB can be confusing as most vendors promise one of a few features without differentiation. Here are some key points to identify the right CASB solution provider for your business.

Check out our list of Top 10 CASB Solutions

• Identify and categorize Shadow IT cloud services employed and determine if they pose a risk.
• Measure risks and choose cloud services that meet internal and industry security and compliance standards. 
• Ensure the safety of enterprise data stored within the cloud by preventing specific types of sensitive data from getting uploaded in conjunction with tokenizing and encrypting data. 
• Identify possible misuse of the organization’s cloud services. This includes unauthorized activities by insiders and third parties, which may compromise user accounts. 
• Introduce multiple levels of cloud service functionality and data access supported user’s devices, operating systems, and placement. 

Why does legacy CASB need a new approach?

Legacy Cloud Access Security Brokers (CASBs) face several significant drawbacks that necessitate a new approach to cloud security:

1. Operational Complexity:

Legacy CASBs are often standalone solutions, detached from the core security architecture, leading to complexity in synchronizing data protection and security policies. This disjointed setup complicates management and can lead to inconsistent policy enforcement.

2. Limited Deployment Models:

Traditional CASB cyber security solutions use forward and reverse proxies, which are limited to web-based protocols and require extensive infrastructure like log collectors and PAC agents. These deployment models do not provide comprehensive visibility into all cloud applications, particularly unsanctioned ones, and complicate threat prevention.

3. Static Application Signatures:

Legacy CASBs rely on static application libraries and manual signature updates, which cannot keep up with the rapid growth of SaaS applications. This delays identifying and controlling new cloud apps, leaving security gaps.

4. Inadequate Data Protection Integration:

Legacy CASBs often function as standalone DLP tools, which can create inconsistencies in data protection across cloud and on-premises environments. This approach can reduce the effectiveness of data governance and compliance efforts.

5. Complex Deployment and Management:

Deploying legacy CASBs requires significant resources and infrastructure, such as log collectors and PAC configurations. This increases the total cost of ownership (TCO) and reduces operational efficiency.

A modern CASB approach with Strac addresses these issues and provides more effective and comprehensive security. 

CASB Vs DLP

CASBs are cloud-centric and offer tools specifically designed for cloud security challenges, including data protection. DLP solutions provide broader data protection, focusing on preventing data loss across all environments, not just the cloud.

Key Features:

CASB:

• Cloud application discovery and risk assessment.
• Data encryption and tokenization in the cloud.
• User activity monitoring and anomaly detection.
• Policy enforcement across multiple cloud services.

DLP:

• Data classification and identification.
• Real-time monitoring of data activities.
• Policy-based data protection and encryption.
• Incident response and reporting for data breaches.

CASB vs SSPM

CASBs focus on securing cloud services and managing access, while SSPMs are dedicated to monitoring and improving the security posture of SaaS applications. SSPMs offer a more detailed view of SaaS security configurations, identifying and addressing potential vulnerabilities. Both tools are essential for comprehensive cloud security, with CASBs providing broad control over cloud usage and SSPMs ensuring detailed configuration security for SaaS applications.

Key Features

CASB:

• Cloud application discovery and risk assessment.
• Data encryption and tokenization in the cloud.
• User activity monitoring and anomaly detection.
• Policy enforcement across multiple cloud services.

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SSPM:

• Continuous monitoring of SaaS application configurations.
• Identification and remediation of misconfigurations.
• Automated enforcement of security policies.
• Compliance reporting and audit support.

CASB Vs SSE

CASBs specialize in securing cloud services and applications, providing visibility, data security, threat protection, and compliance. SSE offers a broader, integrated security solution that includes CASB functionalities, SWG, ZTNA, and FWaaS, providing comprehensive and unified security.

How Does Strac CASB Help?

Despite CASBs’ capabilities and familiarity with approaches and techniques used to protect data in on-premise setups ring bell, CASBs, however, are a lot different. 

CASBs are often misunderstood. For instance, when CASBs first appeared, it was considered a cloud surveillance solution. However, modern-day CASBs like Strac offer a wide range of capabilities across core compliance, data security, transparency, and threat protection. 

So what else does Strac help us achieve? 

Strac as a comprehensive data loss prevention (DLP) solution helps companies of all sizes:

• Redaction of Sensitive Data: Strac can redact sensitive data and documents across all SaaS platforms (including the likes of Gmail, Slack, Zendesk, and Salesforce) and cloud platforms like AWS and Azure.
• Instant Detection of Sensitive Data Subjects: Strac has the capability to instantly detect Personal Identifiable Information (PII), Personal Health Information (PHI), and other sensitive data subjects that are on the brink of a breach. In such instances, Strac triggers an alarm, notifying customers to take swift action.

• Custom Remediation: Block or Alert or Encrypt sensitive files when shared by users on their Mac or Windows endpoints.

In conclusion, the power of CASBs, particularly Strac, extends far beyond simple surveillance. Its proactive approach to data loss prevention, compliance, and threat detection make it an indispensable tool for robust cloud security strategies.

FAQs:

‍1. What are the primary use cases supported by the CASB?

Understanding the prominent use cases, such as data loss prevention (DLP), threat protection, and compliance, will help you determine if the CASB aligns with your organization's security goals.

2. Can I control activities in managed and unmanaged cloud applications instead of blocking services?

Instead of blocking entire services, ensure you can control specific activities (e.g., file sharing) across all cloud storage services.

3. Can I enforce sensitive data policies in and en route to cloud services and reduce false positives?

Verify that the CASB can enforce data policies across sanctioned and unsanctioned services while minimizing false positives.

4. Do you offer flexible deployment options to meet my requirements?

Ensure the CASB offers flexible deployment options, including on-premises and cloud-based models.

5. Can I detect cloud activity anomalies across any service?

Ensure the CASB can detect anomalies like excessive downloads or suspicious activity across all cloud services.

6. Can I monitor and report on activity in regulated services for compliance?

Confirm that the CASB can monitor and report activities in regulated services to comply with regulations like Sarbanes-Oxley.

7. What types of data protection policies can be enforced?

Inquire about the range of data protection policies the CASB can enforce, such as encryption, tokenization, and access controls, to ensure comprehensive data security.

8. Can I mitigate risks against users with compromised accounts?

Ensure the CASB can identify and protect against compromised user accounts.

9. Can I find and remediate threats and malware in cloud services?

Confirm the CASB's ability to identify and mitigate threats and malware in all cloud services.

10. Do you enhance the value of existing investments by integrating with on-premises solutions?

Check if the CASB can integrate with existing on-premises security solutions like DLP, SIEM, and EDR.

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