CVE-2024-9686

Executive Summary

CVE-2024-9686 is a Missing Authorization vulnerability in the Order Notification for Telegram WordPress plugin. The plugin fails to perform a capability check on the nktgnfw_send_test_message function, allowing any unauthenticated attacker to trigger a test message to the configured Telegram chat via the Telegram Bot API. This can be used for spam, social engineering, or reconnaissance of the site’s Telegram integration.

Affected Component: WordPress plugin order-notification-for-telegram (versions up to and including 1.0.1).

Impact: Unauthenticated attackers can send arbitrary test messages to the Telegram bot chat configured in the plugin settings, potentially leading to spam, phishing, or information disclosure about the site’s Telegram setup.

CVSS Score: 5.3 (Medium) – Network, Low Complexity, No Privileges Required, No User Interaction, Confidentiality/Integrity/Availability impact: None/Low/None.

Patch Status: UNKNOWN / UNPATCHED – No official patch has been released by the vendor as of this analysis.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – Exploit does not affect other components.
• Confidentiality (C): None (N) – No data exposure.
• Integrity (I): Low (L) – Attacker can send test messages, but cannot modify core data.
• Availability (A): None (N) – No denial of service.

Threat Level: Medium. The vulnerability is trivial to exploit and requires no authentication, but the direct impact is limited to sending test messages. However, it can be chained with social engineering or used to verify the existence of a Telegram bot for further attacks.

Deep Dive & Mechanics

The vulnerability resides in the nktgnfw_send_test_message function, which is intended to allow administrators to send a test message to verify the Telegram bot configuration. The function is registered via WordPress AJAX actions (both authenticated and unauthenticated) but lacks a capability check (e.g., current_user_can('manage_options')). This means any unauthenticated visitor can call the AJAX endpoint and trigger a message.

Root Cause: Missing capability check in the function nktgnfw_send_test_message. The code likely uses add_action('wp_ajax_nopriv_nktgnfw_send_test_message', ...) without verifying user permissions.

Attack Flow:

1. Attacker identifies a WordPress site running the vulnerable plugin.
2. Attacker sends a POST request to /wp-admin/admin-ajax.php with action=nktgnfw_send_test_message and optional parameters (e.g., message).
3. The plugin sends a test message to the Telegram chat configured in the settings.
4. The attacker can repeat this to spam the chat or send crafted messages.

WordPress Ecosystem Note: This is a WordPress plugin vulnerability, not related to Apache or Nginx. The issue is in the plugin’s AJAX handler.

Vulnerable vs. Patched Code

Since no official patch is available, the vulnerable code is assumed to be:

Vulnerable Code (version <= 1.0.1):

add_action('wp_ajax_nopriv_nktgnfw_send_test_message', 'nktgnfw_send_test_message');
function nktgnfw_send_test_message() {
    // No capability check
    $message = sanitize_text_field($_POST['message']);
    // Send message via Telegram API
    // ...
}

Patched Code (hypothetical):

add_action('wp_ajax_nopriv_nktgnfw_send_test_message', 'nktgnfw_send_test_message');
function nktgnfw_send_test_message() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $message = sanitize_text_field($_POST['message']);
    // Send message via Telegram API
    // ...
}

The fix requires adding a capability check (e.g., manage_options) before processing the request.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with plugin version <= 1.0.1.
• Telegram bot token and chat ID configured in plugin settings.

Exploit Steps:

1. Identify the target site’s AJAX endpoint: https://target.com/wp-admin/admin-ajax.php.
2. Send a POST request with action=nktgnfw_send_test_message and optional message parameter.

Example cURL command:

curl -X POST https://target.com/wp-admin/admin-ajax.php \
  -d "action=nktgnfw_send_test_message&message=Test+message+from+attacker"

Expected Result: The configured Telegram chat receives the message "Test message from attacker".

Advanced Usage: The attacker can send multiple messages to spam the chat or craft phishing messages.

Blue Team (Detection & Response)

Detection:

• Monitor AJAX requests to admin-ajax.php with action=nktgnfw_send_test_message from unauthenticated users.
• Look for repeated requests to this endpoint from the same IP.
• Check Telegram chat logs for unexpected test messages.

Response:

• Immediately disable the plugin if no patch is available.
• Block the attacker’s IP at the WAF or firewall.
• Review Telegram bot token and chat ID for compromise.
• Notify the site administrator.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action=nktgnfw_send_test_message.
  • Repeated requests from the same IP to the AJAX endpoint.
• Application IOCs:
  • Unexpected test messages in the Telegram chat configured in the plugin.
  • Plugin version <= 1.0.1.
• File IOCs:
  • Presence of the plugin file order-notification-for-telegram/order-notification-for-telegram.php with vulnerable code.

Detection Engineering

YARA Rule

rule Detect_CVE_2024_9686_WordPress_Plugin {
    meta:
        description = "Detects vulnerable Order Notification for Telegram plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-9686"
    strings:
        $vuln_func = "nktgnfw_send_test_message"
        $ajax_hook = "wp_ajax_nopriv_nktgnfw_send_test_message"
        $no_cap_check = "current_user_can" nocase
    condition:
        $vuln_func and $ajax_hook and not $no_cap_check
}

Sigma Rule

title: CVE-2024-9686 - Unauthenticated Telegram Test Message Sending
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated AJAX requests to the vulnerable nktgnfw_send_test_message function
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2024-9686
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: POST
        cs-uri-query|contains: "action=nktgnfw_send_test_message"
    condition: selection
falsepositives:
    - Legitimate admin test messages (rare)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-9686 - Unauthenticated Telegram Test Message Sending"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=nktgnfw_send_test_message"; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Block AJAX requests to nktgnfw_send_test_message from unauthenticated users via WAF rules.
3. Review Telegram bot token and chat ID for any unauthorized messages.

Long-term Fix:

• Apply a capability check (e.g., current_user_can('manage_options')) to the nktgnfw_send_test_message function.
• Monitor the plugin’s repository for an official patch.

Workaround:

• Add a custom filter to restrict AJAX actions:

add_action('wp_ajax_nopriv_nktgnfw_send_test_message', function() {
    wp_die('Unauthorized', 403);
}, 1);

Valters IT
DevSecOps & Cyber Threat Intelligence Expert