Flowise: RBAC Bypass Leading to Unauthorized Workspace Variables Disclosure

Finding — Unauthorized Workspace Variables disclosure via $vars injection (bypasses variables:view)

What’s wrong (code locations)

• Variables for the active workspace are fetched without checking “variables:view” at this call site: flowise-src/ packages/components/src/utils.ts:932
• Runtime variables are resolved from server environment variables: flowise-src/packages/components/src/utils.ts:976
• $vars is always injected into the code execution sandbox: flowise-src/packages/components/src/utils.ts:1782
• The official Variables API is permission-protected (contrast): flowise-src/packages/server/src/routes/variables/ index.ts:11

Why it is a privilege boundary bypass

A user/API key might be denied variables:view (and the /api/v1/variables route enforces it), but they can still:

• call /api/v1/node-custom-function (Finding 1)
• and have $vars pre-populated with all variables for the workspace, including runtime values from process.env

What data is exposed

Inside the custom JS context, $vars contains a flat map of:

• Variable.name -> Variable.value for static variables, and
• Variable.name -> process.env[Variable.name] for runtime variables (type === 'runtime')

This can expose secrets such as database passwords, JWT secrets, SMTP passwords, cloud keys, etc., depending on what the workspace Variables are configured to map.

Recommended fix (minimum)

• Do not inject $vars unless the caller is authorized:
  • enforce variables:view before injecting $vars, or
  • inject only an explicit allowlist of variables needed for the function
• Consider disabling or heavily restricting type=runtime variables in self-hosted environments (or restrict which env keys may be mapped).