CODEWITHSUNDEEP
javascriptjquery
Matteo Bononi 'peorthyr'
Matteo Bononi 'peorthyr'

Reputation: 2220

Hack the behaviour of window.location.replace, use a javascript instead of URL

Is it possible in some way to hack the behaviour of window.location.replace, to fire a JavaScript function (let's say alert) instead of making the user go to the new location?

I'll give you the example, let's say we have this function:

setTimeout(function(){ window.location.replace("#SOMETHING_HERE#"); }, 900);

this is fired when a user clicks on a specific button; the #SOMETHING_HERE# is a placeholder, the administrator can put there a URL via a configuration panel.

Now, we all know clients are weird, and mine has just asked me to find a way to fire a JavaScript instead of redirect the user, well, I'm stuck. Of course I should modify the function bound to the button, but actually I have no access to the code and the only entry point is that panel I've mentioned before, I can only change the value of #SOMETHING_HERE#. Do someone has some clues on how I could for example fire an alert("foo"); ? is that possible in some way?

the answer could be also "NO" and I'll simply say them that we have to find a way to change that code.

Upvotes: 0

Views: 2264

Answers (1)

James Thorpe
James Thorpe

Reputation: 32202

You can prefix your string with javascript::

setTimeout(function(){ window.location.replace("javascript:alert('hello world!')"); }, 900);

This works because the spec for location.replace ends up at the definition for "navigate", which says:

  1. This is the step that attempts to obtain the resource, if necessary. Jump to the first appropriate substep:

...

If the new resource is a URL whose scheme is javascript

Queue a task to run these "javascript: URL" steps, associated with the active document of the browsing context being navigated:

Upvotes: 8

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