As network leaders assess their SD-WAN options, however, what is often missing from their deliberations is how to adequately address security risks. SD-WAN vendors are increasingly embedding security features into their offerings, but these tend to be basic, Layer 3 network controls and not the robust security functions that these environments require.

https://blog.fortinet.com/2018/01/11/do-you-want-an-sd-wan-with-security-features-or-a-secure-sd-wan