GHSA-5h9v-837x-m97r: Flowise: mass assignment enables cross-workspace data takeover

## Summary **Type:** Mass assignment via `Object.assign(entity, body)` -> client-controlled `workspaceId` (and on create, `id`) overwritten on the Dataset entity -> cross-workspace data takeover and IDOR. **File:** `packages/server/src/services/dataset/index.ts` **Root cause:** The Dataset controller/service constructs a `new Dataset()` and copies the request body into it via `Object.assign(...)` without an explicit field allowlist. The request body therefore can include `workspaceId`, `id`, `createdDate`, `updatedDate`. The server only rebinds *some* of these after the assign (e.g. on create, it overwrites `workspaceId` but not `id`; on update, it overwrites `id` but not `workspaceId`). The remaining client-controlled values land directly on the persisted row, breaking workspace isolation. Same root pattern as the dataset entity's sibling controllers and as `DocumentStore` before it was patched in commit 840d2ae. ## Affected Code **File:** `packages/server/src/services/dataset/index.ts` ```ts // create (line 203) and update (line 226) Object.assign(newDataset, body) // <-- BUG: body.id, body.workspaceId accepted ``` **Why it's wrong:** `Object.assign(target, source)` copies every own enumerable property of `source` onto `target`. The TypeORM/SQL persistence layer below it does not strip ownership-bearing columns, so `workspaceId` set in the request body lands as the new `workspaceId` of the persisted row. The DocumentStore patch (commit 840d2ae) demonstrated the intended fix shape (explicit field-by-field allowlist) but it has not been applied to this entity. ## Exploit Chain 1. Attacker is an authenticated member of workspace A. They have a session cookie / JWT for the Flowise web UI. State at this point: attacker can read and write entities scoped to workspace A. 2. Attacker creates a dataset in workspace A via the documented API (or reuses an existing one they own). They note its entity `id`. 3. Attacker issues a `PUT /api/v1/datasets/<id>` (or equivalent endpoint) with a JSON body that includes `"workspaceId": "<workspace-B-id>"` (an arbitrary other workspace's UUID). State at this point: the request reaches the controller as a workspace-A authenticated request. 4. The controller calls `Object.assign(updateEntity, body)`. The body's `workspaceId` overwrites the entity's `workspaceId` field. The persistence layer commits the row. 5. Final state: the dataset row is now owned by workspace B. Workspace B members can see it, modify it, and use it. Workspace A loses access (it no longer satisfies their workspace filter). The original creator's workspace audit shows nothing because the operation looked like a normal update. ## Security Impact **Severity:** High. Cross-workspace boundary violation by any authenticated workspace member. **Attacker capability:** Any authenticated user with permission to update a dataset can move it to any workspace whose UUID they can guess or enumerate (workspace UUIDs are exposed in many API responses, so enumeration is trivial). Datasets hold training / evaluation data scoped to a workspace. Moving a Dataset across workspaces via `workspaceId` overwrite exposes the dataset (rows, schema, references) to the destination workspace. **Preconditions:** Authenticated session with edit permission for the source dataset. No second factor required. Workspace UUIDs are exposed via the `/api/v1/workspaces` listing or via any cross-referenced object's `workspaceId` field, so target enumeration is trivial. **Differential:** PoC-verified by source inspection of the original GHSA-q4pr-4r26-c69r. Patched build (with the suggested fix below) refuses the `workspaceId` field; vulnerable build accepts it and persists it. ## Suggested Fix Already fixed in PR https://github.com/FlowiseAI/Flowise/pull/6051 (allowlist pattern applied). ```ts // Allowlist pattern (matches commit 840d2ae for DocumentStore): const updatedDataset = new Dataset() if (body.<allowed_field_1> !== undefined) updatedDataset.<allowed_field_1> = body.<allowed_field_1> if (body.<allowed_field_2> !== undefined) updatedDataset.<allowed_field_2> = body.<allowed_field_2> // ...whitelist only the documented fields. Never copy id, workspaceId, createdDate, updatedDate from the client. ``` Regression tests should assert that a request body containing `workspaceId`, `id`, `createdDate`, or `updatedDate` is rejected (or at minimum: does not change those columns on the persisted row) for both create and update paths.

A contractor with legitimate access to a Flowise instance shared across multiple business units authenticates to their scoped workspace and queries /api/v1/workspaces to obtain UUIDs for the HR and Finance workspaces. They create a benign-looking dataset in their workspace, note its entity ID, then issue a single PUT /api/v1/datasets/<id> with body {"name": "normal-update", "workspaceId": "<finance-workspace-uuid>"}. The Dataset service calls Object.assign(entity, body), persisting the new workspaceId directly to the database row. The Finance workspace now owns the dataset; Finance team members can view its contents. Simultaneously, the contractor moves a Finance workspace dataset they discovered via workspaceId cross-references into their own workspace, exfiltrating its training rows through their normal read API access. The entire operation appears in logs as two ordinary dataset updates.