Fix missing object-level authorization (IDOR) in TypeScript and Next.js
=======================================================================

Get the user from your authentication inside each route handler and server
action, never from the request, and put one scope in every invoice query:
tenant_id = $tenant AND (owner_id = $user OR $isBillingAdmin). Then detail,
list and export return only readable rows. Answer 404 otherwise, and refuse an
export when any requested ID is out of scope.

Page: https://softwaresecurity.com/fix/missing-authorization/typescript-nextjs/

What is in this archive
-----------------------
missing-authorization/typescript-nextjs/   the project: three implementations of the same code and one test suite
  lib/impl/vulnerable.ts   (vulnerable)
  lib/impl/fixed.ts   (fixed)
  lib/impl/wrong.ts   (a plausible fix that still fails)
run-all.mjs   runs the tests in all three modes and checks the results (Node.js only)
LICENSE-CODE.txt

Run it
------
  Tested with Node.js 26.11.1 (node:sqlite needs 22.13.0 or later without a
  flag; route handlers use the default Node.js runtime); package.json allows
  Node.js ^22.23.2 || ^24.18.1 || >=26.5.1. run-all.mjs needs Node.js 22 or
  later. Supported versions: https://softwaresecurity.com/fix/versions/

  From the missing-authorization/typescript-nextjs folder, install the
  dependencies once (this needs network access):

    npm ci

  Then run the tests. IMPL chooses the implementation the tests load:

    # every test passes
    IMPL=fixed npm test --silent
    # an exploit test fails
    IMPL=vulnerable npm test --silent
    # a test fails
    IMPL=wrong npm test --silent

  The JUnit report is written to reports/junit.xml. To run all three modes and
  check the results in one step, run the harness from this top folder (it needs
  only Node.js; --install runs the install step first):

    node run-all.mjs --install missing-authorization/typescript-nextjs
    node run-all.mjs missing-authorization/typescript-nextjs

Verified
--------
  11 October 2026 on macOS 27.0 (Darwin 27.0.0, arm64), with node 26.11.1, npm
  11.20.0, next 16.4.0, react 19.3.0, vitest 5.0.3 (Vite 8.3.4), typescript
  6.0.3, node:sqlite built in (SQLite 3.53.4), semgrep 1.180.0. Versions and
  results hold for that date: run the tests with your own versions before
  relying on the fix.

Licence
-------
  The code is MIT licensed (LICENSE-CODE.txt). The page text is CC BY 4.0.
