Back 
The answer depends on where you desire to control apps and to what depth of policy controls are required. Next generation firewalls (NGFW) long ago recognized apps in allow or deny policy controls for user identity, content type, and app identity. URL categories in secure web gateways (SWG) were too broad to delineate specific apps and use cases, plus an associated app risk profile. Also, web sites became app like instances with personal logins and features that mirror custom apps to post data, share, like, and personalize. Overtime, SWGs responded with specific app web filtering URL controls given available visibility.
On the IT front, core applications such as customer relationship management (CRM), email, and data storage migrated to the cloud. As a prime example, Microsoft Office 365 is a well recognized leading app suite managed by IT with administration rights. Cloud access security broker (CASB) solutions then developed using vendor-provided cloud APIs for near real-time policy controls and data-at-rest security functions. This led to a dozen or more IT managed cloud apps falling under the domain of CASB API policy controls.
The value of cloud-based apps quickly expanded into thousands of apps where the majority are used by business units and users without IT administrations rights. NGFWs and SWGs could respond with basic allow and deny policy controls for these unmanaged apps outside the domain of IT administration using CASB API policy controls. However, this situation falls short to understand the user, app, instance, risk, activity, and data for policy controls aware of ‘content and context’. Given 95% or more of apps are outside of IT control, they need security controls for safe use beyond just allow or deny. Who is the user, device, and what app, instance, activity, and more importantly, what data is in motion?
While all this activity was developing, another wave was surfacing in the guise of encrypted traffic using SSL/TLS tunnels. Existing on-premises NGFW and SWG appliances faced performance issues if tasked with decrypting and inspecting these encrypted tunnels, even if filtered down by domain, app or URL. CASB API controls were free from this challenge for IT managed apps. Today, many companies see over 80% of their web traffic encrypted for apps and web sites creating a blind spot and putting a heavy dependence on endpoint security to prevent and detect threats, and to prevent data loss and theft.
So, a large void emerged where thousands of apps outside the administration rights of IT and CASB API policy controls, often in encrypted tunnels, were not being inspected by NGFWs or SWGs for data loss or threats. Basic allow or deny policy controls would utilize header metadata of encrypted traffic and known risk app profiles. For many the answer resulted in allowing over a thousand unmanaged apps to enable business units and users, and hoping data leakage and threats are kept in check. The reality of widespread unmanaged cloud app use with data flowing like water in many directions highlighted the lack of visibility and control of current security solutions.
From the beginning, Netskope recognized both managed and unmanaged apps, and while a CASB API provided IT-managed app policy controls, an inline proxy for custom app API-JSON traffic was required for unmanaged apps, and to improve inline activity-based controls for managed apps with data-in-motion. In our previous blog we reviewed five ways vendors could claim ‘any app’ support. The correct answer is a managed and supported library of app templates using machine learning, advanced tools, and humans to quickly learn custom app API traffic, changes or updates in API traffic, and to provide granular policy controls for content and context.
The custom app API proxy falls directly into the intersection of NGFW, SWG and CASB solutions to filter app traffic inline beyond basic allow or deny controls and to leverage DLP to protect data. So yes, inline web filtering is turning into app API-JSON filtering to protect data, prevent and detect threats, and enable unmanaged apps in wide use by business units. With cloud-delivered scale and performance, Netskope provides web and app filtering to converge SWG, CASB, and DLP solutions for all apps, encrypted traffic inspection, and common policy controls in one security platform. Learn more about Next-Gen SWG in our solution brief and white paper.
Read the blog