The Open Connectivity Foundation UPnP specification before 2020-04-17 does not forbid the acceptance of a subscription request with a delivery URL on a different network segment than the fully qualified event-subscription URL, aka the CallStranger issue.
With Rapid7 live dashboards, I have a clear view of all the assets on my network, which ones can be exploited, and what I need to do in order to reduce the risk in my environment in real-time. No other tool gives us that kind of value and insight.
– Scott Cheney, Manager of Information Security, Sierra View Medical Center