CVE-2025-3889

WordPress Simple PayPal Shopping Cart <= 5.1.3 - Insecure Direct Object Reference via 'quantity'

2025-04-30 22:01
Jack Taylor

Strategic Overview

Status
Patched in 5.1.4
Affected Plugin
Simple Shopping Cart
Affected Version
<= 5.1.3
CVSS
5.3Medium
Weakness type
CWE-639 · Authorization Bypass Through User-Controlled Key
CVE
CVE-2025-3889
View all Simple Shopping Cart vulnerabilities

At a glance

CVE-2025-3889 is a medium-severity Authorization Bypass Through User-Controlled Key vulnerability in the Simple Shopping Cart WordPress plugin, affecting versions <= 5.1.3. It carries a CVSS score of 5.3 (reachable over the network; low attack complexity). Exploitation requires no authentication. The issue is fixed in version 5.1.4; sites on affected versions should update now. Disclosed April 2025, reported by Jack Taylor.

Vulnerability Overview

The WordPress Simple Shopping Cart plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 5.1.3 via the 'process_payment_data' due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to change the quantity of a product to a negative number, which subtracts the product cost from the total order cost. The attack will only work with Manual Checkout mode, as PayPal and Stripe will not process payments for a negative quantity.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user.

CWE-639: Authorization Bypass Through User-Controlled Key

Simple Shopping Cart <= 5.1.3 carries this weakness at process_payment_data, and reaching it takes a caller who can reach the endpoint. Authorization bypass through a user-controlled key, often called insecure direct object reference, means the application looks up a record by an identifier from the request without checking that the caller owns it.

Changing a number in the request is enough to read or modify other users' records, which on commerce and membership sites means customer data. For Simple Shopping Cart the fix is 5.1.4: builds <= 5.1.3 are affected, anything from 5.1.4 onward is not.

Remediation

Update to version 5.1.4, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Simple Shopping Cart 5.1.4 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2025-3889https://www.wordfence.com/threat-intel/vulnerabilities/id/41212533-535e-4a9e-a9b8-1240021a3752https://nvd.nist.gov/vuln/detail/CVE-2025-3889

Related records

Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C