GHSA-r4xc-vwqr-3252: Lightdash: Unauthenticated dbt Cloud webhook with path injection leaks API key

Lightdash is an open source business intelligence platform. In affected versions through 0.3213.0, the dbt Cloud webhook POST /api/v1/projects/{projectUuid}/dbt-cloud/webhook has no authentication middleware or signature validation. In packages/backend/src/controllers/projectController.ts, testWebhook() accepts accountId and runId from a job.run.completed request and passes them to createPreviewWithExplores() in packages/backend/src/services/ProjectService/ProjectService.ts. These unsanitized values are interpolated into the server-side dbt Cloud API URL, which is requested with the victim project's API key in the Authorization header. Path traversal through accountId changes the requested path on cloud.getdbt.com without changing its host, so the credential-bearing request reaches an attacker-influenced path on that fixed host. The advisory claims API-key theft, but the supplied evidence does not establish that the attacker can observe the Authorization header. The unauthenticated webhook also allows preview creation. The target must be a dbt Cloud IDE project and the attacker must know its projectUuid; the UUID is not enumerable but can be discovered in shared or multi-tenant contexts. Version 0.3214.0 fixes identifier path traversal and verifies webhook HMAC signatures only when a secret is configured; without a secret, unsigned webhooks continue to be processed.