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CWE-1385

WebSocketにおけるOriginバリデーションの欠落

Missing Origin Validation in WebSockets
脆弱性 作成中
JA

本製品はWebSocketを使用していますが、データまたは通信のソースが有効であることを適切に検証していません。

WebSocketは、クライアントとサーバー間の双方向の低遅延通信(ほぼリアルタイム)を提供します。WebSocketはHTTPとは異なり、クライアントまたはサーバーがメッセージを送信する準備が整うまでチャネルが開いたままになるため、接続が長続きします。HTTPでは、応答が発生すると(通常はすぐに発生します)、トランザクションが完了します。

WebSocketは、ポート80と443上で既存のHTTPプロトコルを活用することができますが、HTTPに限定されるものではありません。WebSocketは、SOP(Same Origin Policy)やCORS(Cross-Origin Resource Sharing)のようなブラウザベースの保護メカニズムによって制限されないクロスオリジンリクエストを行うことができます。明示的なオリジン検証がないため、CSRF 攻撃はより強力になります。

EN

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.

Scope: Confidentiality, Integrity, Availability, Non-Repudiation, Access Control / Impact: Varies by Context; Gain Privileges or Assume Identity; Bypass Protection Mechanism; Read Application Data; Modify Application Data; DoS: Crash, Exit, or Restart
Enable CORS-like access restrictions by verifying the 'Origin' header during the WebSocket handshake.
Use a randomized CSRF token to verify requests.
Use TLS to securely communicate using 'wss' (WebSocket Secure) instead of 'ws'.
Require user authentication prior to the WebSocket connection being established. For example, the WS library in Node has a 'verifyClient' function.
Leverage rate limiting to prevent against DoS. Use of the leaky bucket algorithm can help with this.
Use a library that provides restriction of the payload size. For example, WS library for Node includes 'maxPayloadoption' that can be set.
Treat data/input as untrusted in both directions and apply the same data/input sanitization as XSS, SQLi, etc.
MITRE公式ページ — CWE-1385