Question 225687 in Javascript Question posted in
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Javascript – How to extract information about cookies set by an external domain?

I would like to know if it is possible to obtain information about the host address of the domain from which a cookie was created on my webpage?

I have this sittuation:

  1. I’am on "domain A", where I have a script linked from "domain B".
  2. On "domain B" a method is execuded that sets a cookie on my "domain A".

Is there any way to obtain information that the cookie was created from "domain B"?

I need precise information that the cookie originates from "domain B".

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2

Answers


  1. Chosen as BEST ANSWER
    0

    I've modified the script above and it seems like I've achieved the desired effect:

    <script type="text/javascript">
    let originalSet = Object.getOwnPropertyDescriptor(Document.prototype, 'cookie').set;
    function debugAccess(obj, prop, debugGet){
       Object.defineProperty(obj, prop, {
          set: function(val) {
             let debugObj = {};
             try { Error.captureStackTrace(debugObj, val); }
             catch(e) { debugObj = e; }
             console.log(`cookie: "${val}"nstack trace:n${debugObj.stack.replace('Error', '')}`);
             originalSet.call(this, val);
          }
       });
    }
    debugAccess(Document.prototype, 'cookie');
</script>

    And now I'm getting something like this:

    cookie: "test_cookie3=hello world po 30 sekundach; expires=Tue, 15 Aug 2023 12:39:31 GMT; path=/"
stack trace:

    at HTMLDocument.set [as cookie] (http://creator.domain.local/cart/:61:19)
    at setCookie (http://fedev.pl/cookie.js:9:21)
    at http://fedev.pl/cookie.js:20:3

  2. 0

    Modified answer from here https://stackoverflow.com/a/48185552/2213309

    <script type="text/javascript">
    function debugAccess(obj, prop, debugGet){
        Object.defineProperty(document, prop, {
            set: function(val) {
                let obj = {};
                try { Error.captureStackTrace(obj, val); }
                catch(e) { obj = e; } // this is needed to make it work in FF
                console.log (`cookie: "${val}"nstack trace:n${obj.stack.replace('Error', '')}`);
            }
        });
    debugAccess(document, 'cookie');
</script>

    This should print something like the following to the console every time a piece of js code is writing a cookie.

    cookie: "cookie=chocolate"
stack trace:
set@http://domain.a/test.html:16:17
@http://domain.b/script.js:1:1

    The stack trace can be much longer but the last line should always refer to the initiator script.

    The exact output depends on the browser.

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