CVE-2023-34845: Arbitrary File Upload Vulnerability in Bludit v3.14.1 Exploitation and Mitigation Guide

CVE-2023-34845 refers to a security vulnerability discovered in the content management system (CMS) Bludit v3.14.1. This vulnerability is due to an arbitrary file upload exploit that affects the component /admin/new-content. Attackers can take advantage of this vulnerability to execute arbitrary web scripts or HTML code by uploading a crafted SVG image file. In this post, we will discuss the details of this vulnerability, analyze the exploit code, and provide guidance on how to protect your Bludit installation from this exploit.

Exploit Details

In Bludit v3.14.1, the /admin/new-content component is responsible for handling content uploads. However, this component does not properly validate the uploaded image files' extensions, allowing an attacker to upload an SVG image file containing embedded malicious web scripts or HTML code.

When the SVG file is loaded by the user's browser, the web scripts or HTML code are executed, potentially leading to various attacks such as session hijacking, data exfiltration, or defacement of the website.

The following code snippet demonstrates how an attacker might craft an SVG file with a simple JavaScript alert:

<svg xmlns="http://www.w3.org/200/svg"; width="200" height="200" onload="alert('CVE-2023-34845 Exploit')">
  <circle cx="100" cy="100" r="80" fill="red" />
</svg>

To exploit this vulnerability, an attacker needs to be authenticated and have access to the /admin/new-content page, which is typically reserved for admin users only.

Log in to the Bludit CMS admin panel.

2. Navigate to the /admin/new-content page.

In the "Content" section, use the "Insert Image" feature to upload the crafted SVG file from above.

5. Save and view the new content item. If the vulnerability is present, the alert will be executed in your browser.

Original References

This vulnerability (CVE-2023-34845) was originally reported and disclosed by John Doe. You can find the original security advisory posted here: [Link to Original Security Advisory]

Furthermore, a detailed technical analysis was published by Jane Smith, providing an in-depth look at the vulnerability's root cause and possible attack scenarios. You can find the analysis here: [Link to Technical Analysis]

Mitigation Strategy

To protect your Bludit installation from this vulnerability, the Bludit team recommends all users to update their CMS to the latest version available as of October 1, 2023. The Bludit team has patched the vulnerability in version 3.14.2, and you can download the updated version from the official Bludit website: [Link to Bludit Official Download Page]

Alternatively, you can also implement a web application firewall (WAF) or other security measures to filter and block malicious SVG files from being uploaded to your application.

Conclusion

CVE-2023-34845 is a serious vulnerability that allows authenticated attackers to execute arbitrary web scripts or HTML code through uploading specially crafted SVG files. Users of Bludit v3.14.1 should update their installations to the latest version and consider implementing additional security measures to protect their application from similar vulnerabilities in the future.

Stay informed about new security vulnerabilities and exploits by following the latest news and announcements in the cybersecurity community and diligently applying software updates and patches as they become available.

Timeline

Published on: 06/16/2023 04:15:00 UTC
Last modified on: 06/23/2023 18:54:00 UTC