<![CDATA[Security of Tabbed Browsing]]>Can different web pages opened in the same Opera main window interact with each other?

Until now, I had believed that web pages opened in other tabs could not, for example, read the cookies of my bank website that I am logged into.

For Firefox, using the same tabbed document interface style, I now find the add-on Firefox Multi-Account Containers, which Mozilla writes about:

Keep different kinds of browsing far away from each other (for example, you might use one Container tab for managing your Checking Account and a different Container tab for searching for new songs by your favorite band).

So Firefox seems to need an extension for this tab shielding. Does anyone know what Opera's situation is like?

]]>https://forums.opera.com/topic/30683/security-of-tabbed-browsingRSS for NodeWed, 16 Sep 2026 13:53:03 GMTSun, 27 Jan 2019 20:18:34 GMT60<![CDATA[Reply to Security of Tabbed Browsing on Wed, 30 Jan 2019 05:53:48 GMT]]>No interaction? That's rather strong. Again, websites can open login forms in other (pop-up) windows as well as tabs. Lacking either of those - and presuming you aren't using some malicious add-on (extension) - there will be no communication between unrelated pages - whether those pages are in separate tabs or separate windows.

That does still leave history attacks (where a page has a bunch of links where you can't see them and checks to see if they are marked as sites you have visited or not) but either clearing history regularly or using a private window can prevent that.

]]>https://forums.opera.com/post/163585https://forums.opera.com/post/163585Wed, 30 Jan 2019 05:53:48 GMT<![CDATA[Reply to Security of Tabbed Browsing on Wed, 30 Jan 2019 04:04:41 GMT]]>Thank you very much for your reply, @sgunhouse. I hadn't considered this scenario, and of course you're right.

Is it correct to say that no interaction is possible between different Opera windows and therefore it would be the safest to start websites with such sensitive data as bank websites each in its own window [Ctrl+N], and not to visit other websites in that window?

When Opera is running, I see a lot of active opera.exe in the Windows task manager. As I understand it, this is because each tab runs as a separate process, so that a single crashing tab/web page cannot crash the entire browser. Probably from this I had inferred wrongly or only half rightly that one window's tabs cannot interact with each other under any circumstances.

]]>https://forums.opera.com/post/163581https://forums.opera.com/post/163581Wed, 30 Jan 2019 04:04:41 GMT<![CDATA[Reply to Security of Tabbed Browsing on Mon, 28 Jan 2019 07:11:53 GMT]]>By definition, if page A opens page B it can interact with that page. Otherwise they should not interact.. Some pages open a login in a new window or tab, the login will fail if it can't talk to the original page somehow, hence every browser has to support that.

]]>https://forums.opera.com/post/163423https://forums.opera.com/post/163423Mon, 28 Jan 2019 07:11:53 GMT