ssl - Loading http content on https website

Question

I'm thinking about my website architecture that's using https.. I now have a CDN server hosting images , css and more static files.

The website itself is using HTTPS for securing sensitive costumer data. Will using the static images , loaded by for example 'http://cdn.example.com/images/test.jpg' on a website 'https://www.example.com' popup a "Loading insecure data" message?

So loading external NOT SECURED data on a SECURED website. Will this be causing a popup warning "Loading insecure data, continue?"?

Thx!

Answer 1

Yes.

If a page is loaded over HTTPS then every resource it uses should also be loaded over HTTPS.

Otherwise a man-in-the-middle could replace images with misleading ones (or ones that exploit buffer overflow issues in browsers to execute code) and scripts with ones that do different things (such as leak data to the third party).