websocket

Audit WebSocket implementations for security vulnerabilities and message validation gaps.

12|1|Updated Feb 9, 2026
One-click install
npx skills add https://github.com/florianbuetow/claude-code --skill websocket-florianbuetow
Or copy as Structured Prompt for Agent
Please help me install this Agent Skill.
Skill: websocket
Source: https://github.com/florianbuetow/claude-code/tree/main/plugins/appsec/skills/websocket
Command: npx skills add https://github.com/florianbuetow/claude-code --skill websocket-florianbuetow

SYSTEM DOCUMENTATION & REQUIREMENTS

💡 This Skill includes references (resource) components.

What problem does it solve?

This Skill addresses critical security vulnerabilities in WebSocket implementations, protecting against common attack vectors like hijacking, unauthorized access, and data breaches.

Core Features & Use Cases

  • Vulnerability Auditing: Identifies missing authentication on upgrade, Cross-Site WebSocket Hijacking (CSWSH) risks, lack of message validation, and unencrypted transport.
  • Security Hardening: Provides actionable insights and patterns to secure long-lived, bidirectional communication channels.
  • Use Case: Audit a real-time chat application's WebSocket backend to ensure that only authenticated users can connect and that messages are properly validated to prevent injection attacks.

Quick Start

Analyze the security of the WebSocket handlers in the project for potential vulnerabilities.

Frequently Asked Questions about websocket

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I audit WebSocket connections for security vulnerabilities?

WebSocket Cross-Site WebSocket Hijacking (CSWSH) occurs when an application accepts unauthorized cross-origin upgrade requests. You prevent it by enforcing strict origin validation and requiring authentication tokens during the initial WebSocket upgrade handshake to block unauthorized connections.

How do I prevent Cross-Site WebSocket Hijacking (CSWSH)?

You prevent CSWSH by enforcing strict origin validation and requiring authentication on the WebSocket upgrade handshake. Auditing message handlers ensures only authenticated users can connect and interact with the bidirectional communication channel.

Does my WebSocket implementation need message validation and rate limiting?

Yes, WebSocket implementations require message validation and rate limiting to prevent injection attacks and resource exhaustion. Auditing message handlers ensures incoming data is properly sanitized and request frequency is controlled across long-lived connections.

What are the security risks of using unencrypted ws:// in production WebSocket applications?

Using unencrypted ws:// in production exposes WebSocket traffic to interception and tampering. Auditing your implementation identifies unencrypted transport and recommends upgrading to secure wss:// to protect data transmitted across bidirectional channels.

Can I use semgrep for pattern detection in WebSocket security audits?

Yes, you can use semgrep to detect insecure patterns in WebSocket implementations. The security audit integrates with semgrep for deep tracing of message handling and identifies vulnerabilities like missing authentication and inadequate message validation.