Iframe in Chrome error: Failed to read 'localS

Question

I have a web app which uses localStorage. Now we want to embed this web app on other (third-party) sites via iframe. We want to provide an iframe embed similar to youtube so that other websites can embed our web app in an iframe. Functionally it is the same as if it wouldn't be embedded. But it does not work. Chrome prints the error message:

Uncaught SecurityError: Failed to read the 'localStorage' property from 'Window': Access is denied for this document.

I just do the following check (in the iframe):

if (typeof window.localStorage !== 'undefined') {
    // SETUP SESSION, AUHT, LOCALE, SETTINGS ETC
} else {
    // PROVIDE FEEDBACK TO THE USER
}

I checked my security settings in Chrome like described in another Stackoverflow Thread but it doesn't work. Is there any change to make embedding possible without the need of adjusting (default) security settings of most modern browsers?

To give more information, we use Ember-CLI for our web app and turned on CSP (more info about the Ember-CLI CSP). Could CSP cause our web app to throw security errors?

Answer 1

On the following URL: chrome://settings/content/cookies uncheck "Block third-party cookies".

Answer 2

I ran into this problem in my phone, I couldn't open a certain site with chrome. It took me some time to find the cookies on my phone, when I found it, I saw that my cookies was blocked.

go to your Settings --> Site settings --> Cookies

and allow the site to save and read cookie data, make sure that you don't block third-party cookies!

I hope this helps you.

Answer 3

I checked all the answers but ended up not finding anything. Then I realized what browser I'm using. If you're using Brave (Chromium Based), you will get this error if your shield is up. Try lowering your shield.

Answer 4

According to this

This exception is thrown when the "Block third-party cookies and site data" checkbox is set in Content Settings.
To find the setting, open Chrome settings, type "third" in the search box, click the Content Settings button, and view the fourth item under Cookies.