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Agreed. But what's more intriguing to me is that the proposed "solution" is to add yet another hack on top of that (rel=noopener), instead of doing something t

Agreed. But what's more intriguing to me is that the proposed "solution" is to add yet another hack on top of that (rel=noopener), instead of doing something to fix the broken behavior of target=_blank. I doubt that many sites rely on this broken behavior. And even if they do, browsers could still block it and show some warning to the user "Hey, this tab that just opened wants to change the URL of this other tab [allow, always, nope, never]", just like they do for popup windows or sites with broken SSL certs. Does someone with more experience in these kind of issues know why it was decided to put the responsibility of fixing this on individual websites (rel=noopener) instead of browsers (blocking the URL changing or showing a warning)?

reitanqild 10y ago
> I doubt that many sites rely on this broken behavior. Any web based system where a pop up dialog is opened to allow the user to select something that is then inserted into the original page?
- epidemian 10y ago
  Good call! I guess i haven't seen any of those. But i've seen some internal web based systems that relied too heavily on popup windows and started breaking when tabbed browsing became a thing and brosers started blocking popup windows by default, so i don't doubt that there are probably systems out there relying on this weird behavior of target=_blank. For those systems, though, i'd imagine most of them would have these popup windows on the same origin, right? So having browsers prevent child windows changing their parent's location if they are cross-origin seems like a sensible idea, or am i missing something else?
  - panic 10y ago
    There are more than 1 billion websites. If just 0.1% of sites use target=_blank like that, you'd be breaking a million sites with your change. You can't use arguments like "I haven't seen any of those" or it "seems like a sensible idea" when making decisions like this.
    - epidemian 10y ago
      The "I haven't seen any of those" was just as a comment on why i couldn't think of possible uses for this target=_blank behavior, not a justification for the proposed change (what a lame justification that would be! :) That being said, i don't see how the proposal of browsers blocking popup windows from redirecting the parent window (if it's cross-origin) by default is any different from, for instance, them blocking popup windows from opening unless it was a user action that triggered them, which all browsers started doing by default quite some time ago. Could you elaborate on why this wouldn't be a sensible solution?
      - panic 10y ago
        It does seem like a sensible solution, but the web isn't exactly a sensible place. People use terribly-written web sites for all sorts of things that are important to them in their life. Changes that potentially break these sites shouldn't be taken lightly.
      - bzbarsky 10y ago
        Should the parent window be able to navigate the popup window, even if it's cross origin? If not, now you're suggesting some sort of asymmetric security checks that depend on something that's not just the origins. Security checks that, chances are, will be easy to evade by malicious actors. At least I haven't thought of a non-evadable one here yet.
    - adrianN 10y ago
      Lots of websites used to use Java applets, but browsers decided they're not worth the security risk and made users jump through more and more hoops to start embedded Java.
    - lazyjones 10y ago
      > you'd be breaking a million sites with your change. Websites relying on such obscure misbehavior are already broken in my book. Fixing them would solve the problem better and cause fewer new problems for everyone else.
  - PinguTS 10y ago
    For example Typo3 is using that, when you need to select something to be inserted/referenced into the current record. So any, Typo3 based website would break.
    - deleted 10y ago
      [deleted]
- roywiggins 10y ago
  Probably there are, but they're hardly likely to rely on it working cross-origin, and if they are they almost deserve to have it broken...
  - reitanqild 10y ago
    Not sure but I would think anything that use a pop up to login using social media account would like to get an event back when successfully logged in?
    - sjwright 10y ago
      Social media networks are well placed to get their little embedded code snippets updated across the web. And chances are, these links are being generated by a cross-origin javascript library anyway. If you wanted to be very generous, browsers could auto-whitelist origins of every javascript library loaded in the page. In any remaining cases, there should still be some method to white-list the current behavior, e.g. rel=allowopener.
circlingthesun 10y ago
This common with OAuth flows. User clicks "login with x", a popup opens that redirects to an authorization page on x. The user then logs in on x, and gets redirected back to origin that takes the token in the hash fragment, and passes it back to the page the user is trying to login to, via window.opener.
- bigblind 10y ago
  Most of these use postMessage.
  - dgoldstein0 10y ago
    probably window.opener.postMessage. Though that doesn't excuse window.opener.location not being blocked in the name of the Same-Origin Policy...
    - bzbarsky 10y ago
      "location" is not blocked cross-origin, because that allows you to navigate windows you opened, or subframes of yourself, even if they happen to not be same-origin with you at the moment. And it's been this way for over 20 years, and sites commonly depend on it. :( So what you're suggesting is either some sort of asymmetric "same-origin" checks or .... something.
      - stormbrew 10y ago
        I don't really see the problem with making this asymmetrical. The security implications of a frame navigating its parent and a parent navigating its child frame seem very clearly different to my mind. If you're suggesting it would be technically difficult, I'm extremely skeptical of that. The origin's relationship to the target frame should not be impossible to discern, and I'd be a little shocked if it isn't taken into account elsewhere.
        bzbarsky 10y ago

reitanqild 10y ago

> I doubt that many sites rely on this broken behavior. Any web based system where a pop up dialog is opened to allow the user to select something that is then inserted into the original page?

epidemian 10y ago
Good call! I guess i haven't seen any of those. But i've seen some internal web based systems that relied too heavily on popup windows and started breaking when tabbed browsing became a thing and brosers started blocking popup windows by default, so i don't doubt that there are probably systems out there relying on this weird behavior of target=_blank. For those systems, though, i'd imagine most of them would have these popup windows on the same origin, right? So having browsers prevent child windows changing their parent's location if they are cross-origin seems like a sensible idea, or am i missing something else?
- panic 10y ago
  There are more than 1 billion websites. If just 0.1% of sites use target=_blank like that, you'd be breaking a million sites with your change. You can't use arguments like "I haven't seen any of those" or it "seems like a sensible idea" when making decisions like this.
  - epidemian 10y ago
    The "I haven't seen any of those" was just as a comment on why i couldn't think of possible uses for this target=_blank behavior, not a justification for the proposed change (what a lame justification that would be! :) That being said, i don't see how the proposal of browsers blocking popup windows from redirecting the parent window (if it's cross-origin) by default is any different from, for instance, them blocking popup windows from opening unless it was a user action that triggered them, which all browsers started doing by default quite some time ago. Could you elaborate on why this wouldn't be a sensible solution?
    - panic 10y ago
      It does seem like a sensible solution, but the web isn't exactly a sensible place. People use terribly-written web sites for all sorts of things that are important to them in their life. Changes that potentially break these sites shouldn't be taken lightly.
    - bzbarsky 10y ago
      Should the parent window be able to navigate the popup window, even if it's cross origin? If not, now you're suggesting some sort of asymmetric security checks that depend on something that's not just the origins. Security checks that, chances are, will be easy to evade by malicious actors. At least I haven't thought of a non-evadable one here yet.
  - adrianN 10y ago
    Lots of websites used to use Java applets, but browsers decided they're not worth the security risk and made users jump through more and more hoops to start embedded Java.
  - lazyjones 10y ago
    > you'd be breaking a million sites with your change. Websites relying on such obscure misbehavior are already broken in my book. Fixing them would solve the problem better and cause fewer new problems for everyone else.
- PinguTS 10y ago
  For example Typo3 is using that, when you need to select something to be inserted/referenced into the current record. So any, Typo3 based website would break.
  - deleted 10y ago
    [deleted]
roywiggins 10y ago
Probably there are, but they're hardly likely to rely on it working cross-origin, and if they are they almost deserve to have it broken...
- reitanqild 10y ago
  Not sure but I would think anything that use a pop up to login using social media account would like to get an event back when successfully logged in?
  - sjwright 10y ago
    Social media networks are well placed to get their little embedded code snippets updated across the web. And chances are, these links are being generated by a cross-origin javascript library anyway. If you wanted to be very generous, browsers could auto-whitelist origins of every javascript library loaded in the page. In any remaining cases, there should still be some method to white-list the current behavior, e.g. rel=allowopener.

circlingthesun 10y ago

This common with OAuth flows. User clicks "login with x", a popup opens that redirects to an authorization page on x. The user then logs in on x, and gets redirected back to origin that takes the token in the hash fragment, and passes it back to the page the user is trying to login to, via window.opener.

bigblind 10y ago
Most of these use postMessage.
- dgoldstein0 10y ago
  probably window.opener.postMessage. Though that doesn't excuse window.opener.location not being blocked in the name of the Same-Origin Policy...
  - bzbarsky 10y ago
    "location" is not blocked cross-origin, because that allows you to navigate windows you opened, or subframes of yourself, even if they happen to not be same-origin with you at the moment. And it's been this way for over 20 years, and sites commonly depend on it. :( So what you're suggesting is either some sort of asymmetric "same-origin" checks or .... something.
    - stormbrew 10y ago
      I don't really see the problem with making this asymmetrical. The security implications of a frame navigating its parent and a parent navigating its child frame seem very clearly different to my mind. If you're suggesting it would be technically difficult, I'm extremely skeptical of that. The origin's relationship to the target frame should not be impossible to discern, and I'd be a little shocked if it isn't taken into account elsewhere.
      - bzbarsky 10y ago