CVE Vulnerabilities

CVE-2021-41120

Authorization Bypass Through User-Controlled Key

Published: Oct 05, 2021 | Modified: Aug 12, 2022
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
5 MEDIUM
AV:N/AC:L/Au:N/C:P/I:N/A:N
RedHat/V2
RedHat/V3
Ubuntu

sylius/paypal-plugin is a paypal plugin for the Sylius development platform. In affected versions the URL to the payment page done after checkout was created with autoincremented payment id (/pay-with-paypal/{id}) and therefore it was easy to predict. The problem is that the Credit card form has prefilled credit card holder field with the Customers first and last name and hence this can lead to personally identifiable information exposure. Additionally, the mentioned form did not require authentication. The problem has been patched in Sylius/PayPalPlugin 1.2.4 and 1.3.1. If users are unable to update they can override a sylius_paypal_plugin_pay_with_paypal_form route and change its URL parameters to (for example) {orderToken}/{paymentId}, then override the SyliusPayPalPluginControllerPayWithPayPalFormAction service, to operate on the payment taken from the repository by these 2 values. It would also require usage of custom repository method. Additionally, one could override the @SyliusPayPalPlugin/payWithPaypal.html.twig template, to add contingencies: [SCA_ALWAYS] line in hostedFields.submit(…) function call (line 421). It would then have to be handled in the function callback.

Weakness

The system’s authorization functionality does not prevent one user from gaining access to another user’s data or record by modifying the key value identifying the data.

Affected Software

Name Vendor Start Version End Version
Paypal Sylius 1.0.0 (including) 1.2.4 (excluding)
Paypal Sylius 1.3.0 (including) 1.3.1 (excluding)

Extended Description

Retrieval of a user record occurs in the system based on some key value that is under user control. The key would typically identify a user-related record stored in the system and would be used to lookup that record for presentation to the user. It is likely that an attacker would have to be an authenticated user in the system. However, the authorization process would not properly check the data access operation to ensure that the authenticated user performing the operation has sufficient entitlements to perform the requested data access, hence bypassing any other authorization checks present in the system. For example, attackers can look at places where user specific data is retrieved (e.g. search screens) and determine whether the key for the item being looked up is controllable externally. The key may be a hidden field in the HTML form field, might be passed as a URL parameter or as an unencrypted cookie variable, then in each of these cases it will be possible to tamper with the key value. One manifestation of this weakness is when a system uses sequential or otherwise easily-guessable session IDs that would allow one user to easily switch to another user’s session and read/modify their data.

Potential Mitigations

References