Wowza generally installs with enough permissions in order to work without the user having to worry too much about permissions. So it can be seen as quite generous on some platforms, as in OS X - which is generally similar to a desktop installation. For example, if installed and run as stand-alone mode then Wowza is running as the user logged into OS X at that time, so long as that user also has admin/root privileges.
You can lock this down manually to your specific administrator user, for example user "paul" in group "staff" (stop Wowza first)
chmod -R 700 WowzaStreamingEngine-X.X.X
chown -R paul:admin WowzaStreamingEngine-X.X.X
That would prevent anyone apart from "paul" (or root of course) from cd'ing into the Wowza installation path.