What does Cloud Access Security Broker mean?
A CASB provides security and governance controls between users and cloud services. Depending on the architecture, it works inline in data traffic, via APIs against cloud platforms or combines both methods.
The Problem: SaaS Is Growing Faster Than Governance and Data Inventory
Departments are introducing cloud services, personal and business clients are being used in parallel, and sensitive files are leaving controlled repositories. A pure app list shows this risk, but does not yet provide a meaningful decision.
Blocks that are too aggressive shift work to shadow processes. Shares that are too wide, on the other hand, ignore uploads, external shares, OAuth links, and data movement between managed and private instances.
Employees are allowed to use cloud storage for business purposes, but should not upload confidential documents to private accounts. To do this, the app, tenant, user action, data class, and exception process must be recognized together.
Separate CASB controls by view and action
Inline and API-based methods answer different questions.
Discovery
Make cloud app usage, risk, volume, and user groups visible.
Inline Control
Control login, upload, download, share and other actions during the session.
API Control
Check data, approvals and configurations directly in connected SaaS services.
Tenant Control
Differentiate between business and personal instances of the same service.
Data Security
Connect DLP, classification, and context to app actions.
Governance
Set App Owner, Release, Exception, Review, and Incident Process.
What needs to be checked before making a decision?
- Which SaaS services and tenants are actually being used?
- Which user actions create a relevant risk?
- Which data classes must be recognized?
- Is inline view sufficient or is an API connection required?
- Who evaluates new apps and approves exceptions?
- How are false positives and business interruptions handled?
Definition: CASB does not replace SaaS configuration hardening, contract review, or full data governance. API access and supported actions differ per service and license.
How SourcingBlox Adopts CASB from a Risk Perspective
We start with a few prioritized apps, data classes and user actions.
SaaS & Risk Discovery
Capture apps, tenants, data movements, owners, and business needs.
Control Design
Design and test inline, API, tenant, and DLP controls per use case.
Governance
Establish onboarding, app evaluation, exceptions, incidents and regular reviews.
Typical mistakes
- Treat CASB only as a shadow IT list.
- Do not distinguish between private and business clients.
- Block all risky apps across the board.
- Do not check API permissions and operational responsibility.
Frequently Asked Questions
What is the difference between inline and API CASB?
Inline controls evaluate ongoing sessions and actions. API controls check supported data and configurations directly within connected cloud services.
Can CASB differentiate personal SaaS accounts?
Depending on the service, data path, license and supported tenant control function, a distinction may be possible. It has to be technically tested.
Does CASB always need DLP?
Not for every app detection. However, coordinated data classification is central to content-related decisions.
Translating SaaS risks into controllable use cases.
We connect discovery, data classes, user actions, and a viable governance process.
Related Content
Sources and further information
Supported SaaS services, actions, and API permissions must be verified before implementation.