Medium

Sylius PayPal Plugin has an Order Manipulation Vulnerability after PayPal Checkout

Disclosed: 19.03.2025
Updated: 11.10.2026 10:22

A discovered vulnerability allows users to modify their shopping cart after completing the PayPal Checkout process and payment authorization. If a user initiates a PayPal transaction from a product page or the cart page and then returns to the order summary page, they can still manipulate the cart contents before finalizing the order. As a result, the order amount in Sylius may be higher than the amount actually captured by PayPal, leading to a scenario where merchants deliver products or services without full payment.

Impact

Users can exploit this flaw to receive products/services without paying the full amount.
Merchants may suffer financial losses due to underpaid orders.
Trust in the integrity of the payment process is compromised.

Patches

The issue is fixed in versions: 1.6.2, 1.7.2, 2.0.2 and above.

Workarounds

To resolve the problem in the end application without updating to the newest patches, there is a need to overwrite PayPalOrderCompleteProcessor with modified logic:

php

<?php

declare(strict_types=1);

namespace App\Processor;

use Sylius\Bundle\PayumBundle\Model\GatewayConfigInterface;
use Sylius\Component\Core\Model\OrderInterface;
use Sylius\Component\Core\Model\PaymentInterface;
use Sylius\Component\Core\Model\PaymentMethodInterface;
use Sylius\PayPalPlugin\Manager\PaymentStateManagerInterface;

final class PayPalOrderCompleteProcessor
{
    public function __construct(private readonly PaymentStateManagerInterface $paymentStateManager) {
    }

    public function completePayPalOrder(OrderInterface $order): void
    {
        $payment = $order->getLastPayment(PaymentInterface::STATE_PROCESSING);
        if ($payment === null) {
            return;
        }

        /** @var PaymentMethodInterface $paymentMethod */
        $paymentMethod = $payment->getMethod();
        /** @var GatewayConfigInterface $gatewayConfig */
        $gatewayConfig = $paymentMethod->getGatewayConfig();

        if ($gatewayConfig->getFactoryName() !== 'sylius.pay_pal') {
            return;
        }

        try {
            $this->verify($payment);
        } catch (\Exception) {
            $this->paymentStateManager->cancel($payment);

            return;
        }

        $this->paymentStateManager->complete($payment);
    }

    private function verify(PaymentInterface $payment): void
    {
        $totalAmount = $this->getTotalPaymentAmountFromPaypal($payment);

        if ($payment->getOrder()->getTotal() !== $totalAmount) {
            throw new \Exception();
        }
    }

    private function getTotalPaymentAmountFromPaypal(PaymentInterface $payment): int
    {
        $details = $payment->getDetails();

        return $details['payment_amount'] ?? 0;
    }
}

IMPORTANT

For PayPalPlugin 2.x change:

php

$gatewayConfig->getFactoryName() !== 'sylius.pay_pal'

php

$gatewayConfig->getFactoryName() !== SyliusPayPalExtension::PAYPAL_FACTORY_NAME

Also there is a need to overwrite CompletePayPalOrderListener with modified logic:

php

<?php

declare(strict_types=1);

namespace App\EventListener\Workflow;

use App\Processor\PayPalOrderCompleteProcessor;
use Sylius\Component\Core\Model\OrderInterface;
use Symfony\Component\Workflow\Event\CompletedEvent;
use Webmozart\Assert\Assert;

final class CompletePayPalOrderListener
{
    public function __construct(private readonly PayPalOrderCompleteProcessor $completeProcessor)
    {
    }

    public function __invoke(CompletedEvent $event): void
    {
        /** @var OrderInterface $order */
        $order = $event->getSubject();
        Assert::isInstanceOf($order, OrderInterface::class);

        $this->completeProcessor->completePayPalOrder($order);
    }
}

And to overwrite CaptureAction with modified logic (if you didn't have it already):

php

<?php

declare(strict_types=1);

namespace App\Payum\Action;

use Payum\Core\Action\ActionInterface;
use Payum\Core\Exception\RequestNotSupportedException;
use Payum\Core\Request\Capture;
use Sylius\Component\Core\Model\PaymentInterface;
use Sylius\Component\Core\Model\PaymentMethodInterface;
use Sylius\PayPalPlugin\Api\CacheAuthorizeClientApiInterface;
use Sylius\PayPalPlugin\Api\CreateOrderApiInterface;
use Sylius\PayPalPlugin\Payum\Action\StatusAction;
use Sylius\PayPalPlugin\Provider\UuidProviderInterface;

final class CaptureAction implements ActionInterface
{
    public function __construct(
        private CacheAuthorizeClientApiInterface $authorizeClientApi,
        private CreateOrderApiInterface $createOrderApi,
        private UuidProviderInterface $uuidProvider,
    ) {
    }

    /** @param Capture $request */
    public function execute($request): void
    {
        RequestNotSupportedException::assertSupports($this, $request);

        /** @var PaymentInterface $payment */
        $payment = $request->getModel();
        /** @var PaymentMethodInterface $paymentMethod */
        $paymentMethod = $payment->getMethod();

        $token = $this->authorizeClientApi->authorize($paymentMethod);

        $referenceId = $this->uuidProvider->provide();
        $content = $this->createOrderApi->create($token, $payment, $referenceId);

        if ($content['status'] === 'CREATED') {
            $payment->setDetails([
                'status' => StatusAction::STATUS_CAPTURED,
                'paypal_order_id' => $content['id'],
                'reference_id' => $referenceId,
                'payment_amount' => $payment->getAmount(),
            ]);
        }
    }

    public function supports($request): bool
    {
        return
            $request instanceof Capture &&
            $request->getModel() instanceof PaymentInterface
        ;
    }
}

After that, register services in the container when using PayPal 1.x:

yaml

Sylius\PayPalPlugin\EventListener\Workflow\CompletePayPalOrderListener:
    class: App\EventListener\Workflow\CompletePayPalOrderListener
    public: true
    arguments:
        - '@Sylius\PayPalPlugin\Processor\PayPalOrderCompleteProcessor'
    tags: 
        - { name: 'kernel.event_listener', event: 'workflow.sylius_order_checkout.completed.complete', priority: 100 }
    
Sylius\PayPalPlugin\Processor\PayPalOrderCompleteProcessor:
    class: App\Processor\PayPalOrderCompleteProcessor
    public: true
    arguments:
        - '@Sylius\PayPalPlugin\Manager\PaymentStateManagerInterface'

Sylius\PayPalPlugin\Payum\Action\CaptureAction:
    class: App\Payum\Action\CaptureAction
    public: true
    arguments:
        - '@Sylius\PayPalPlugin\Api\CacheAuthorizeClientApiInterface'
        - '@Sylius\PayPalPlugin\Api\CreateOrderApiInterface'
        - '@Sylius\PayPalPlugin\Provider\UuidProviderInterface'
    tags:
        - { name: 'payum.action', factory: 'sylius.pay_pal', alias: 'payum.action.capture' }

or when using PayPal 2.x:

yaml

sylius_paypal.listener.workflow.complete_paypal_order:
    class: App\EventListener\Workflow\CompletePayPalOrderListener
    public: true
    arguments:
        - '@sylius_paypal.processor.paypal_order_complete'
    tags: 
        - { name: 'kernel.event_listener', event: 'workflow.sylius_order_checkout.completed.complete', priority: 100 }
    
sylius_paypal.processor.paypal_order_complete:
    class: App\Processor\PayPalOrderCompleteProcessor
    public: true
    arguments:
        - '@sylius_paypal.manager.payment_state'

sylius_paypal.payum.action.capture:
    class: App\Payum\Action\CaptureAction
    public: true
    arguments:
        - '@sylius_paypal.api.cache_authorize_client'
        - '@sylius_paypal.api.create_order'
        - '@sylius_paypal.provider.uuid'
    tags:
        - { name: 'payum.action', factory: 'sylius.paypal', alias: 'payum.action.capture' }

For more information

If you have any questions or comments about this advisory:

Open an issue in Sylius issues
Email us at security@sylius.com

Affected software

Click a technology to see all vulnerabilities affecting it.

Platform	Package	Vulnerable versions	Fixed in
Composer package	sylius/paypal-plugin	< 1.6.2, >= 1.7.0, < 1.7.2, >= 2.0.0, < 2.0.2	1.6.2, 1.7.2, 2.0.2

References

CVSS score 6.5/10

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-472
Platform: Composer
Package: sylius/paypal-plugin
Disclosed: 19.03.2025
Updated: 11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-hxg4-65p5-9w37 - CC BY 4.0

Vulnerability history: sylius/paypal-plugin

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries: 3
First → latest: 10.2021 03.2025
Without a fix: 0
Exploited in attacks: 0

Severity breakdown

High 1
Medium 2

Disclosures per year

2021: 1
2022: 0
2023: 0
2024: 0
2025: 2
2026: 0

19.03.2025

Sylius PayPal Plugin has an Order Manipulation Vulnerability after PayPal Checkout this entry

Medium · 6.5 CVE-2025-30152 < 1.6.2, >= 1.7.0, < 1.7.2, >= 2.0.0, < 2.0.2 1.6.2, 1.7.2, 2.0.2
17.03.2025

Sylius PayPal Plugin Payment Amount Manipulation Vulnerability

Medium · 6.5 CVE-2025-29788 < 1.6.1, >= 1.7.0, < 1.7.1, >= 2.0.0, < 2.0.1 1.6.1, 1.7.1, 2.0.1
06.10.2021

Sylius PayPal Plugin allows unauthorized access to Credit card form, exposing payer name and not requiring 3DS

High · 7.5 CVE-2021-41120 >= 1.0.0, < 1.2.4, >= 1.3.0, < 1.3.1 1.2.4, 1.3.1

Know which vulnerabilities affect your application

With the DockRay integration and software inventory enabled, DockRay checks reported component versions against known vulnerabilities and notifies you about confirmed matches. Coverage depends on the supported technology and available advisory data.

Connect your application