--- a/plugins/mod_component.lua	Wed Dec 16 10:55:04 2020 +0100
+++ b/plugins/mod_component.lua	Fri Dec 18 22:29:44 2020 +0100
@@ -193,6 +193,10 @@
 end
 
 function stream_callbacks.streamopened(session, attr)
+	if not attr.to then
+		session:close{ condition = "improper-addressing", text = "A 'to' attribute is required on stream headers" };
+		return;
+	end
 	if not hosts[attr.to] or not hosts[attr.to].modules.component then
 		session:close{ condition = "host-unknown", text = tostring(attr.to).." does not match any configured external components" };
 		return;