Introduction
Attackers can gain full administrative access to a WordPress site running Simpler Checkout simply by knowing or guessing an order ID. This authentication bypass, tracked as CVE-2025-7642, impacts e-commerce operators using Simpler Checkout versions 0.7.0 through 1.1.9 and puts all site data and customer information at risk.
Simpler Checkout is a WordPress plugin designed to streamline the WooCommerce checkout process. While not as ubiquitous as WooCommerce itself, it is used by e-commerce sites seeking to reduce friction and increase conversions. The plugin integrates deeply with order management and user authentication flows, making any security flaw in these areas especially impactful.
Technical Information
CVE-2025-7642 is caused by a critical flaw in the authentication logic of the Simpler Checkout plugin. Specifically, the vulnerability resides in the simplerwc_woocommerce_order_created function. When a WooCommerce order is created, this function is responsible for handling post-order logic, including user authentication state changes. However, the function does not properly verify the identity of the user associated with a given order ID.
As a result, an unauthenticated attacker can craft a request referencing a valid order ID. The plugin then logs the attacker in as the user linked to that order. If the order ID belongs to an administrator (for example, from a test order), the attacker is granted full administrative privileges. This is a textbook case of CWE-288: Authentication Bypass Using an Alternate Path or Channel.
No public code snippet is provided, but the flaw is confirmed by multiple advisories and the plugin's codebase (see hooks.php#L7).
Proof of Concept
In the case of the Simpler Checkout plugin for WordPress, versions 0.7.0 through 1.1.9 contain an authentication bypass vulnerability. This flaw allows unauthenticated users to gain administrative access to the WordPress site. The vulnerability arises from improper validation of user input during the authentication process, enabling attackers to manipulate requests and bypass standard authentication mechanisms. By exploiting this, an attacker can perform administrative actions without proper credentials, potentially compromising the entire site.
References: Wordfence Advisory
Detection Methods
Detecting authentication bypass vulnerabilities, such as those found in WordPress plugins like Simpler Checkout, requires a multifaceted approach. These vulnerabilities can allow unauthorized access to sensitive areas of a website, making their timely identification crucial.
1. Log Analysis:
Regularly reviewing server and application logs is essential. Indicators of compromise (IoCs) may include:
- Unusual login attempts from unfamiliar IP addresses.
- Multiple failed login attempts followed by a successful one, especially if the successful attempt lacks proper authentication.
- Access to administrative areas without corresponding login events.
2. Monitoring User Activity:
Implementing tools to monitor user behavior can help identify anomalies:
- Sudden changes in user roles or permissions without proper authorization.
- Creation of new administrative accounts without legitimate approval.
- Unusual times of access, such as administrative actions during off-hours.
3. Code Review and Vulnerability Scanning:
Regularly auditing the codebase of plugins and themes can uncover potential vulnerabilities:
- Look for functions that handle authentication and ensure they are implemented securely.
- Use automated vulnerability scanners to detect known issues in third-party plugins.
4. Implementing Security Plugins:
Utilize security plugins that offer:
- Real-time monitoring of login attempts.
- Alerts for suspicious activities.
- Firewall protection to block malicious requests.
5. Regular Updates and Patch Management:
Ensure that all plugins, themes, and the WordPress core are updated regularly:
- Developers often release patches for known vulnerabilities.
- Subscribing to security advisories can provide timely information on vulnerabilities and their fixes.
6. User Education:
Educate users and administrators about security best practices:
- Encourage the use of strong, unique passwords.
- Implement multi-factor authentication (MFA) where possible.
- Regularly review and audit user permissions.
By integrating these detection methods, organizations can enhance their ability to identify and mitigate authentication bypass vulnerabilities, thereby strengthening their overall security posture.
Affected Systems and Versions
- Product: Simpler Checkout plugin for WordPress
- Affected versions: 0.7.0 through 1.1.9 (inclusive)
- Any WordPress site running these plugin versions is vulnerable
Vendor Security History
No prior major vulnerabilities have been publicly associated with Simpler Checkout. The vendor's response time and patching practices are not detailed in public sources as of this writing.