Though some might argue that it's inherently insecure, SDN has changed for the better in recent years, allowing it to be implemented securely
Several security experts suggest that software-defined networking (SDN) is natively unsecure. They say it removes hardware boundaries such as firewalls that maintain security. They say SDN reveals new, unprotected surfaces to attack. These experts put forth a number of SDN vulnerabilities.
Perhaps those experts are thinking of a classic, yet immature SDN. "SDN has changed a lot in five years," says Vik Mehta, CEO, VastEdge, a software application services firm with an SDN practice. As we learn more about the technology, maybe we can agree that there are two sides to the SDN security coin. (Also see SDN in 2014: More of everything.)