I am trying to change the value in the cors header in wowza. Currently it always comes back as * no matter what the settings are on crossdomain.xml file or anywhere else. I am trying to restrict source domains with cors. Any advice?
The crossdomain.xml file is for flash clients. You can configure CORS per this article. If you upgraded from a version of Wowza Streaming Engine earlier than 4.4.0 then you will need to either add CORS by hand for that application or create a new application.
You can ban connections from referring domains as shown in this article. You can also ban specific IP addresses by following the instructions in this article.