How to restrict a specific group from being added to a space in Confluence or how to make a specific

[seungjai Lee]

Is there a way to restrict certain groups from being added to a space in Confluence? If not, is there a way to allow only users belonging to the confluence-administrator (confluence admin) group to search for a specific group when searching for a group when giving permission to a group in space?

[Radek Dostál]

From what I remember it's a plain text form POST, you don't need the UI to "search", it's just there to suggest plain text values but you don't need it to add any data/objects to the POST itself so long as you enter the username/groupname.

Ergo either, you would need to tinker with the page in javascript, to sort of prevent non-technical users from entering "forbidden" content, or to allow only specific users to do so. Not so trivial unless you're good in js. And, js will not stop technical users, although it will stop vast majority of them.

To make it fireproof, you'd need to tinker with it from the server, reverse proxy may be one place where to filter out the requests and stop them (but that is really questionable and I doubt it would work any good, I can think of a few technical limitations).

Better would be to write a very small plugin which would implement a servlet filter, to stand in front of the POST endpoint - thus it can reliably stop the request IF the form content is forbidden, since you can actually read the data, determine if it contains any forbidden groups, and you can also do server-side permission validations whether the current user is a global administrator or not.