If you have a reverse proxy in front of Jira you can modify the headers to alter default XSS settings. We use Apache with mod_headers to embed the Service Desk Portal into our Confluence intranet:

Header set X-Frame-Options "allow-from http://intranet.xxx.xxx/"
Header set Content-Security-Policy "frame-ancestors 'self' intranet.xxx.xxx" 

This used to work in Server a few years ago, and then it got blocked after, I believe it was, some XSS lockdowns.

There hasn't been a way since. And it's incredibly useful. There seems to be no way to create a form that can be turned into a ticket, outside of having the form send an email to your email channel, but then you are forced to manually assign the reporter. What a mess. This would simplify some of that. Not all, but some.

+1

This would be really helpful!

+1 - Hey Atlassian.  Let's get this done.  Assign this to a product manager.  No brainer.  Or at least make it easy to iframe.

A basic embed of the portal has worked fine for a long time, (at least a year) until a recent update initiated:

Content-Security-Policy: frame-ancestors 'self'

And now it doesn't work anymore...

We had our portal embedded in both our corporate website and in our confluence server installation. It was great. 
(anyone know how to fix that by the way?  )

If this was possible, we could embed our ticketing system with Confluence, where we keep manuals and other end user related information (along with the knowledge base). A widget or what not for this would be fine.

This would be really useful and should be out of the box functionality.

need this

There is a similar feature request in Confluence: https://jira.atlassian.com/browse/CONF-26038