FirstBlood-#164Can know who are attending an HackerBack event

On 2021-05-11, codersanjay reported:

The following endpoint is present in source code.

It seems like it will show status of attendees who are attending an event.

But after sending POST/GET request to this end point, it was throwing 200OK but no content.

I then realised, may be a header should be added which I saw in the source code drpanel.

Sent a modified request.

It was leaking info of who are attending the event.

I also see the ID of old event.Tried sending same request with old event id.


PII info leak.


Endpoint: /attendees/event.php?q=560720

Parameter: x-site-req

Payload: nil

FirstBlood ID: 13
Vulnerability Type: Info leak

/attendees/event can be seen on the HackerBack.html page but has a blank response. Upon further inspection and from making use of the web app, you will notice you can add certain headers in order to interact with this endpoint. An old event ID leaks PII information about attendees.

Respect Earnt: 1500000
RESPECT ($RSP) is an experimental cryptocurrency based on the Ethereum blockchain with the mission to show respect to those who deserve it. We are testing it out on our FirstBlood hackevent.