Trigger.dev: Unauthenticated Realtime Stream Data Injection via Run FriendlyId

Summary

The POST handler for /realtime/v1/streams/:runId/:streamId has no authentication. Any entity that knows or guesses a run friendlyId can inject arbitrary data into its realtime stream.

Vulnerability Details

File: apps/webapp/app/routes/realtime.v1.streams.$runId.$streamId.ts

The action handler (line 17) has no auth wrapper. The code comment says: "Plain action for backwards compatibility with older clients that don't send auth headers."

The run lookup at line 29 uses where: { friendlyId: runId } with NO environment scoping (runtimeEnvironmentId is not checked), so production runs are accessible.

Run friendlyIds follow predictable patterns (e.g., run_1234abcd).

Steps to Reproduce

# No authentication required
curl -X POST "http://localhost:8030/realtime/v1/streams/run_KNOWN_ID/stream_1"   -H "Content-Type: application/json"   -d '{"injected": "data"}'

Impact

Unauthenticated data injection into any run realtime stream. Cross-environment access (no scoping).