What is a Cloud Access Security Broker (CASB)
A Cloud Access Security Broker (CASB) is a security solution that sits between an organization's on-premises infrastructure and a cloud service provider's infrastructure. It acts as a gatekeeper to enforce security policies, ensure compliance, and protect data as it moves between the organization's network and cloud applications. CASBs provide visibility into cloud usage, control over data, threat protection, and compliance enforcement, helping organizations secure their cloud environments effectively.
How Does a CASB Work?
- Visibility and Discovery: CASBs act as a central hub, initially focusing on identifying and understanding all the cloud services your users are interacting with. This includes sanctioned applications approved by IT and shadow IT which are unsanctioned applications used without IT knowledge.
- Policy Creation and Enforcement: IT administrators define security policies that CASBs enforce. These policies can cover various aspects like access controls, data security measures (encryption, DLP), and threat protection protocols (malware scanning).
- Data Flow Monitoring and Control: CASBs become the middleman for data flowing between users and cloud services. They monitor and analyze this data flow, enforcing the pre-defined security policies. This may involve actions including data loss prevention (DLP), threat protection, access control, anomaly detection and threat mitigation and compliance reporting.
Four Pillars of CASBs
CASB solutions operate based on four key pillars: Compliance, Visibility, Data Security, and Threat Detection.
- Visibility: The first pillar of CASBs is visibility. CASBs offer detailed visibility into cloud service usage across an organization, including both sanctioned and unsanctioned applications. This includes monitoring user activities, data flows, and interactions with cloud services. In addition, it also Identifies and manages unauthorized cloud applications used by employees, helping organizations understand the full scope of cloud usage.
- Data Security: With data security as the second pillar, CASBs ensure sensitive data is protected through encryption, tokenization, and data loss prevention (DLP) techniques. This includes securing data at rest, in transit, and in use within cloud environments. It enforces data security policies to control data sharing and access, preventing unauthorized data exposure.
- Threat Protection: Threat protection is the third pillar, CASBs identify and mitigate threats through real-time monitoring of user behavior and cloud activities. This includes detecting anomalies, malware, and suspicious activities. They provide tools and processes for responding to and mitigating security incidents, ensuring quick remediation of threats.
- Compliance: The last pillar, Compliance is achieved by CASBs by helping organizations comply with industry regulations and standards by enforcing policies that ensure data privacy and security. They provide audit logs, compliance reports, and documentation to demonstrate adherence to regulatory requirements and internal policies.
How is CASB Deployed?
The three main deployment models of CASB include API-based deployment, proxy-based deployment and agent-based deployment.
API-Based Deployment
This model leverages APIs provided by cloud service providers to integrate directly with the cloud platforms. It allows the CASB to access and control data and user activities without needing to route traffic through the CASB.
Its key advantages include providing deep visibility and control, enforcing policies directly within the cloud service, and being generally easy to deploy as it doesn't require changes to network traffic.
On the other hand, limitations may include not providing real-time enforcement or comprehensive coverage for all cloud services.
Proxy-Based Deployment
Proxy-based development includes two types of models namely:
- Forward Proxy: Positioned between the users and the cloud services, this model routes traffic through the CASB. It requires configuration changes on user devices or network infrastructure to redirect traffic.
- Reverse Proxy: Positioned between the cloud services and the users, this model routes traffic from the cloud service through the CASB. It typically involves DNS configuration changes to intercept traffic.
Proxy-based deployments offer advantages such as providing real-time visibility and control, enforcing policies on any cloud service, and are effective for both managed and unmanaged devices. Drawbacks include introducing latency, may require more complex deployment and maintenance, and can be bypassed if users access cloud services directly.
Agent-Based Deployment
The third type of deployment involves installing software agents on user devices that monitor and control cloud access. These agents can enforce security policies and provide visibility into cloud usage.
Benefits include offering granular control over user activities, providing detailed visibility, and is effective for managing access from any network. Limitations include requiring installation and maintenance of agents on all user devices, and impact on device performance, and may face resistance from users.
What Security Capabilities Do CASBs Offer?
- Visibility and Control: CASBs provide comprehensive visibility into cloud usage, including sanctioned and unsanctioned (shadow IT) applications. This allows organizations to identify and control how cloud services are being used.
- Data Loss Prevention (DLP): CASBs can help prevent sensitive data from being exfiltrated from the cloud. They can do this by identifying sensitive data, such as financial information or personally identifiable information (PII), and then blocking.
- Threat Protection: CASBs can help protect organizations from cloud-based threats, such as malware and ransomware. They can do this by scanning cloud traffic for malicious content and blocking access to malicious websites.
- Access Control: CASBs can be used to enforce access control policies for cloud applications. This includes controlling who can access cloud applications, what they can do within those applications, and from what devices they can access them.
- Compliance: CASBs can help organizations comply with industry regulations and data privacy laws. They can do this by providing logging and auditing capabilities that can be used to track user activity in the cloud.
- Cloud Governance: CASBs can help organizations establish and enforce cloud governance policies. This includes policies for cloud service selection, data security, and user access.
Benefits of CASBs
Some of the key advantages of CASBs include:
- Enhanced Visibility and Control: CASBs shed light on your cloud environment, giving you insights into both sanctioned applications and those used without IT approval (shadow IT). This newfound visibility allows you to make informed decisions about cloud usage, control access, and enforce security policies.
- Data Loss Prevention (DLP): Data security is paramount. CASBs act as guardians of your sensitive information by identifying and protecting it. They can prevent leaks by blocking unauthorized data transfers or encrypting data at rest and in transit.
- Threat Protection: The cloud isn't immune to cyberattacks. CASBs act as a shield against cloud-based threats like malware and ransomware. They can scan cloud traffic, identify malicious content, and block access to harmful websites or applications.
- Compliance Management: Navigating the complex world of regulations can be a challenge. CASBs can simplify compliance by providing tools to monitor and control data flow according to industry standards and regulations like GDPR, HIPAA, and CCPA.
- Improved Cloud Governance: CASBs empower you to establish and enforce clear cloud governance policies. These policies can cover aspects like cloud service selection, data security practices, and user access controls, ensuring a secure and well-managed cloud environment.
- Reduced Risk from Shadow IT: Shadow IT, the use of unsanctioned cloud applications, can introduce security vulnerabilities. CASBs help identify and manage shadow IT, letting you assess risks and mitigate them.
- Granular Access Control: CASBs enable you to implement granular access controls for cloud applications. You can define who can access specific applications, what actions they can perform within them, and from which devices they can access them.
Use Cases of CASBs
Some common use cases of CASBs include:
- Gaining Visibility and Control over Cloud Applications: Many organizations use numerous cloud services (SaaS), making it difficult to track activity. CASBs provide a centralized platform to monitor and manage sanctioned and unsanctioned applications, offering insights into cloud usage patterns and potential risks.
- Data Loss Prevention (DLP): Sensitive data breaches can be devastating. CASBs help prevent data exfiltration by identifying critical information and enforcing controls like blocking unauthorized transfers or encrypting data at rest and in transit.
- Strengthening Compliance Posture: CASBs simplify compliance by providing tools to monitor and control data activity according to the prevailing standards. They can generate audit reports to demonstrate adherence to regulations.
- Insider Threat Detection and Mitigation: Malicious actors can exploit insider privileges. CASBs monitor user activity and can detect anomalous behaviors, such as unusual download volumes or repeated high-risk actions, indicating potential insider threats.
- Securing Cloud Storage and Protecting Against Malware: Cloud storage can harbor malware. CASBs can scan files for malware detection and leverage sandboxing to detect zero-day threats. They can also enforce session controls to prevent malware upload in real-time.
- Securing Applications on Personal Devices: Employees using personal devices for work can introduce security risks. CASBs can offer Contextual Access Control, allowing or restricting access to approved cloud resources based on the device and user context, without compromising user privacy.
- Governance and Access Control: Robust cloud governance is essential. CASBs help establish and enforce policies around cloud service selection, data security practices, and user access controls. They can also implement granular access controls for specific applications and functionalities.
Difference Between CASB and SASE
| Feature | CASB | Secure Access Service Edge (SASE) |
|---|---|---|
| Type | Security solution | Security framework |
| Primary Focus | Security and compliance of cloud services | Network security and connectivity for remote and distributed users |
| Functionality | Provides visibility, access control, data loss prevention (DLP), threat protection for cloud applications | Integrates networking (SD-WAN) and security functions (CASB, ZTNA) into a unified cloud service |
| Deployment | Cloud-based, API mode | Cloud-based |
| Scalability | Scalable to cover multiple cloud services and applications | Highly scalable to support large, distributed networks and remote users. |
| Benefits | Monitors user activity in Dropbox, enforces data encryption in Salesforce | Provides secure access to cloud applications from any device, protects against malware and other threats |
| Performance | Can impact performance depending on deployment and integration. | Optimized for performance across distributed networks and remote users. |
Conclusion
In conclusion, a Cloud Access Security Broker (CASB) is a critical security solution for organizations navigating the complexities of cloud computing. By acting as a gatekeeper between on-premises infrastructure and cloud services, CASBs provide essential functions like visibility, policy enforcement, data protection, threat detection, and compliance management.
Cloud access security broker vendors empower organizations to monitor and manage cloud usage effectively, safeguard sensitive data through encryption and data loss prevention measures, mitigate cloud-based threats such as malware, and enforce access controls to ensure regulatory compliance.
Cloud access security broker solutions play a pivotal role in enhancing enterprise security posture, governance, and operational efficiency in the cloud era.
People Also Ask
A Cloud Access Security Broker definition is a security checkpoint between a company's internal system and a cloud service provider's system. It helps enforce security policies and protects data as it moves to and from the cloud.
The four pillars of CASB are:
- Visibility: Provides insights into cloud usage, users, and data.
- Compliance: Ensures that cloud usage meets regulatory and internal compliance requirements.
- Data Security: Protects sensitive data through encryption, data loss prevention, and more.
- Threat Protection: Detects and responds to cloud-based threats, such as malware and unauthorized access.
The three deployment models of CASB are:
- API-based: Integrates directly with cloud service APIs to provide security controls.
- Proxy-based: Uses a proxy to intercept traffic between users and cloud services.
- Agent-based: Installs agents on devices to monitor and control cloud access.
CASB enhances security by providing comprehensive visibility into cloud activities, enforcing security policies, detecting and mitigating threats, and protecting sensitive data through encryption and data loss prevention measures.
CASB is important because it helps organizations secure their cloud environments, ensuring that data remains protected, compliance requirements are met, and potential threats are detected and mitigated effectively. It provides the necessary tools to manage and secure cloud usage in a scalable and efficient manner.
