vulns.co
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mcp by GKData.io

WebSocket hunting

Treat the socket as an API with a worse auth story. Handshake, first message, then every subscribe. Cookie plus missing Origin is CSWSH.

Playbooks

  • WebSocket Hunting - Treat the socket as an API with a worse auth story. Handshake, first message, then every subscribe.

Gadgets

  • IDOR parameter - The param is inventory until you prove a second user can read or write the object.
  • WebSocket IDOR / missing auth - Subscribe to another user's channel, replay a privileged event, or skip the HTTP auth that the REST API has.

Payloads

  • WebSocket - Handshake and first-frame probes. Swap in a victim cookie / Origin to test CSWSH and channel IDORs.

Checklists

  • WebSockets - Handshake, first frame, then every subscribe. Treat it as an API with a worse auth story.

Workflows

  • WebSocket channel authorization - Verify handshake origin, token binding, subscription authorization, and unsubscribe behavior using two test accounts. Subscribe only to channels and messages created for the assessment.

Questions

What is CSWSH?

Cross-site WebSocket hijack: a foreign page opens the socket as the victim because the handshake uses a cookie and does not check Origin.

GraphQL subscriptions?

Same tests. Channel names that are user IDs are IDORs.

This page is the public form of hunt_brief("websocket") on the MCP connector. Authorized testing only.