CWE-1385

Missing Origin Validation in WebSockets
AI Translation Available

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

Status
incomplete
Abstraction
variant
Web Based Web Server

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
Impacts
varies by context gain privileges or assume identity bypass protection mechanism read application data modify application data dos: crash, exit, or restart

Potential Mitigations

Phases:
implementation architecture and design
Descriptions:
• Use a randomized CSRF token to verify requests.
• Require user authentication prior to the WebSocket connection being established. For example, the WS library in Node has a 'verifyClient' function.
• Use a library that provides restriction of the payload size. For example, WS library for Node includes 'maxPayloadoption' that can be set.
• Enable CORS-like access restrictions by verifying the 'Origin' header during the WebSocket handshake.
• Use TLS to securely communicate using 'wss' (WebSocket Secure) instead of 'ws'.
• Leverage rate limiting to prevent against DoS. Use of the leaky bucket algorithm can help with this.
• Treat data/input as untrusted in both directions and apply the same data/input sanitization as XSS, SQLi, etc.