CVE-2025-47451

Executive Summary

CVE-2025-47451 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Product Quantity Dropdown For Woocommerce WordPress plugin, developed by Silverplugins217. This plugin is designed to replace the standard WooCommerce quantity input field with a dropdown selector. The vulnerability allows an attacker to forge requests on behalf of an authenticated administrator, potentially leading to unauthorized changes to plugin settings or configurations. The CVSS v3.1 base score is 4.3 (Medium), with a low attack complexity but requiring user interaction. No public proof-of-concept (PoC) or exploit code is currently available, and the vendor has not released a patch. This report provides a comprehensive analysis, detection strategies, and mitigation recommendations for this WordPress ecosystem vulnerability.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. The plugin is not managed through NPM, PyPI, Go, or Ruby ecosystems. However, as a WordPress plugin, it is part of a supply chain where site administrators must manually update or patch the component. The lack of a vendor patch increases the risk of exploitation through social engineering or automated attacks targeting unpatched sites.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack can be launched remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – The attacker does not need prior authentication.
• User Interaction (UI): Required (R) – The victim must click a link or visit a malicious page.
• Scope (S): Unchanged (U) – The vulnerable component remains the same.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Limited ability to modify data (e.g., plugin settings).
• Availability (A): None (N) – No impact on service availability.

Threat Level: Medium. The vulnerability requires user interaction and only affects integrity, but it can be chained with other attacks (e.g., stored XSS) to escalate privileges.

Deep Dive & Mechanics

The CSRF vulnerability in the Product Quantity Dropdown For Woocommerce plugin arises from a lack of nonce validation or CSRF tokens in administrative actions. When an authenticated WordPress administrator performs actions such as saving plugin settings, the plugin does not verify that the request originated from the legitimate admin interface. An attacker can craft a malicious HTML page or email that, when visited by an admin, triggers a forged request to change plugin settings (e.g., disabling quantity dropdowns, altering dropdown options, or injecting malicious JavaScript). The attack exploits the trust that WordPress has in the authenticated user's browser session.

WordPress Ecosystem Context: This is a typical CSRF issue in WordPress plugins where developers omit nonce checks in admin-facing forms. The vulnerability is specific to the plugin's admin interface and does not affect the core WordPress or WooCommerce systems.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is presumed to be in the plugin's admin handler functions. A typical vulnerable pattern in WordPress plugins is:

// Vulnerable: No nonce verification
function save_plugin_settings() {
    if ( isset($_POST['submit']) ) {
        update_option('pqd_settings', $_POST['pqd_options']);
    }
}
add_action('admin_post_save_pqd_settings', 'save_plugin_settings');

A patched version would include a nonce check:

// Patched: Nonce verification added
function save_plugin_settings() {
    if ( isset($_POST['submit']) && wp_verify_nonce($_POST['_wpnonce'], 'pqd_save_settings') ) {
        update_option('pqd_settings', $_POST['pqd_options']);
    }
}
add_action('admin_post_save_pqd_settings', 'save_plugin_settings');

Without the vendor patch, administrators must implement a virtual patch via a Web Application Firewall (WAF) or disable the plugin.

Exploitation & Lab Setup

Red Team (Attack Simulation)

1. Setup: Deploy a WordPress instance with WooCommerce and the vulnerable plugin (version <= 1.2). Create an admin user account.
2. Craft Payload: Create an HTML page that auto-submits a form to the plugin's settings endpoint:

   <html>
   <body>
   <form action="http://target/wp-admin/admin-post.php" method="POST">
       <input type="hidden" name="action" value="save_pqd_settings">
       <input type="hidden" name="pqd_options[disable]" value="1">
       <input type="submit" value="Click me">
   </form>
   <script>document.forms[0].submit();</script>
   </body>
   </html>
   

3. Deliver: Host the page on an attacker-controlled server and trick an authenticated admin into visiting it (e.g., via phishing email).
4. Result: The plugin settings are altered without the admin's consent.

Blue Team (Defense & Detection)

1. Monitor: Watch for unusual POST requests to /wp-admin/admin-post.php with action=save_pqd_settings from unexpected referrers.
2. Harden: Implement CSRF tokens manually via a custom plugin or WAF rule.
3. Audit: Regularly review plugin code for missing nonce checks.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-post.php with action=save_pqd_settings and no _wpnonce parameter.
• Logs: WordPress debug log entries showing unexpected settings changes.
• File: Modified plugin options in the wp_options table (e.g., pqd_settings).
• Behavior: Plugin settings changed without admin interaction.

Detection Engineering

YARA Rule

rule Detect_CSRF_Vulnerable_Plugin {
    meta:
        description = "Detects missing nonce in Product Quantity Dropdown For Woocommerce plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-47451"
    strings:
        $func = "admin_post_save_pqd_settings"
        $nonce = "_wpnonce" nocase
    condition:
        $func and not $nonce
}

Sigma Rule

title: CSRF Exploitation Attempt Against Product Quantity Dropdown Plugin
id: 8f3a2b1c-4d5e-6f7a-8b9c-0d1e2f3a4b5c
status: experimental
description: Detects POST requests to admin-post.php with action save_pqd_settings without nonce
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-query|contains: "admin-post.php"
        cs-uri-query|contains: "action=save_pqd_settings"
    filter:
        cs-uri-query|contains: "_wpnonce"
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions if nonce is present
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-47451 CSRF Attempt Against Product Quantity Dropdown Plugin";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"/wp-admin/admin-post.php"; http_uri;
    content:"action=save_pqd_settings"; http_client_body;
    pcre:"/^(?!.*_wpnonce).*$/P";
    sid:1000001;
    rev:1;
    reference:cve,2025-47451;
    classtype:attempted-admin;
    priority:2;
)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is released.
2. Virtual Patching: Use a WAF (e.g., ModSecurity) to block requests to admin-post.php with action=save_pqd_settings that lack a valid nonce.
3. Code Fix: Add wp_nonce_field() to the plugin's admin form and wp_verify_nonce() in the handler.
4. User Education: Train administrators to avoid clicking suspicious links while logged into WordPress.
5. Monitoring: Enable WordPress debug logging and monitor for unexpected settings changes.

Valters IT Signature:
This report was generated by Valters IT DevSecOps AI. All detection rules are provided as-is for educational and defensive purposes. Always test in a non-production environment before deployment.