Now, you can explicitly set the Transport Layer Security (TLS) version for individual Azure App Service and Azure Functions hosted apps.
TLS is a protocol that provides privacy and data integrity between two communicating applications. It's the most widely deployed security protocol. TLS is used for web browsers and other applications that require data to be securely exchanged over a network. TLS is widely used for file transfers, VPN connections, instant messaging, and VoIP.
Over time, multiple versions of TLS have been released to mitigate different vulnerabilities. TLS 1.2 is the most current version available for apps running on Azure App Service.
To learn how to update the TLS version, and to learn about the impact of setting the TLS version for your apps, read the App Service team blog.