CWE-1385: Missing Origin Validation in WebSockets

MITRE CWE weakness

Description

The product uses a WebSocket, but it does not properly verify that the source of data or communication is valid.

WebSockets provide a bi-directional low latency communication (near real-time) between a client and a server. WebSockets are different than HTTP in that the connections are long-lived, as the channel will remain open until the client or the server is ready to send the message, whereas in HTTP, once the response occurs (which typically happens immediately), the transaction completes. A WebSocket can leverage the existing HTTP protocol over ports 80 and 443, but it is not limited to HTTP. WebSockets can make cross-origin requests that are not restricted by browser-based protection mechanisms such as the Same Origin Policy (SOP) or Cross-Origin Resource Sharing (CORS). Without explicit origin validation, this makes CSRF attacks more powerful.

Common consequences

• Confidentiality, Integrity, Availability, Non-Repudiation, Access Control: Varies by Context, Gain Privileges or Assume Identity, Bypass Protection Mechanism, Read Application Data, Modify Application Data, DoS: Crash, Exit, or Restart

Mitigations

Implementation — Enable CORS-like access restrictions by verifying the 'Origin' header during the WebSocket handshake.

Implementation — Use a randomized CSRF token to verify requests.

Implementation — Use TLS to securely communicate using 'wss' (WebSocket Secure) instead of 'ws'.

Architecture and Design — Require user authentication prior to the WebSocket connection being established. For example, the WS library in Node has a 'verifyClient' function.

Implementation — Leverage rate limiting to prevent against DoS. Use of the leaky bucket algorithm can help with this.

References

• CWE page: https://cwe.mitre.org/data/definitions/1385.html
• CWE list: https://cwe.mitre.org/data/index.html