Spree API has Authenticated Insecure Direct Object Reference (IDOR) via Order Modification

Summary

An Authenticated Insecure Direct Object Reference (IDOR) vulnerability was identified that allows an authenticated user to retrieve other users’ address information by modifying an existing order. By editing an order they legitimately own and manipulating address identifiers in the request, the backend server accepts and processes references to addresses belonging to other users, subsequently associating those addresses with the attacker’s order and returning them in the response.

Details

Affected Component(s)

• Authenticated user order management
• Address association logic
• Order update endpoint(s) Affected Endpoint(s):
• /api/v2/storefront/checkout

The application fails to enforce proper object-level authorization when updating an existing order. While the user is authenticated and authorized to modify their own order, the backend does not verify that the supplied address identifiers belong to the same authenticated user.

PoC

Preconditions

• Valid authenticated user account

Step 1: Log-in using a valid user, in this case [email protected] Step 2: Visualize current user’s addresses

Request GET /account/addresses

The following screenshot shows [email protected] address.

<img width="336" height="375" alt="User Address" src="https://github.com/user-attachments/assets/ceb1f214-7ac0-40b0-af22-6fe9d21254bb" />

Step 3: Initialize the Shopping Cart

Request POST /api/v2/storefront/cart HTTP/1.1

From the response, extract the token marked in bold.

Step 4: Legitimate Order Edit Request

Using the obtained order token A1cram_6cFWpoj4V1yPkuQ1767113871701 perform an edit order request in order to add a custom billing address

Request PATCH /api/v2/storefront/checkout

{
    "include": "billing_address",
    "order": {
      "email": "[email protected]",
      "bill_address_attributes": {
        "firstname":"CTF","lastname":"Tester","address1":"123 Main St",
        "city":"Andorra la Vella","zipcode":"AD100","country_iso":"AD"
      },
      "ship_address_attributes": {
        "firstname":"CTF","lastname":"Tester","address1":"123 Main St",
        "city":"Andorra la Vella","zipcode":"AD100","country_iso":"AD"
      }
    }
  }