We have micro-service that allows CORS using the Access-Control-Allow-Origin
. It works fine. However we have a complicated setup:
subdomain-A.welt.de
has an iFrame that points to subdomain-B.welt.de
. subdomain-B.welt.de
calls the micro-service (somewhere else) via XHR
and requires CORS.
Within that iFrame, and only there, subdomain-B.welt.de
sends null
as Origin
-header for every XHR
-request.
I am not absolutely certain on what's the cause of this and in my research I stumbled upon document.domain
, but as I am uncertain I don't know if that is something to consider (or the right way to fix whatever is happening here).