CVE-2023-44275: OPNsense before 23.7.5 XSS Vulnerability Exploitation Details, Code Snippets, and Relevant Links

Hello everyone, today we will be discussing a vulnerability that was present in an earlier version of the OPNsense firewall software. The vulnerability, titled CVE-2023-44275, affects OPNsense before 23.7.5, and allows an attacker to exploit a Cross-Site Scripting (XSS) issue via the index.php column_count parameter to the Lobby Dashboard. In this long read, we will explore the details of this vulnerability, provide code snippets to demonstrate the issue, and give links to the original references and documentation.

The Vulnerability: CVE-2023-44275

OPNsense is a powerful open-source firewall and routing software that aims to provide a high level of security for networks. Built on the FreeBSD operating system, it is widely used by organizations and individual users who want a comprehensive and easy-to-use security solution. However, older versions of OPNsense (before 23.7.5) were affected by an XSS vulnerability that could compromise the security of the firewall software.

The vulnerability in question, CVE-2023-44275, allows an attacker to inject malicious scripts into web pages viewed by other users, potentially stealing sensitive information, impersonating users, or carrying out other malicious activities. This XSS exploit specifically targets the 'column_count' parameter in the Lobby Dashboard, which is typically used to specify the number of columns in the dashboard layout.

Exploit Details

An attacker can exploit CVE-2023-44275 by crafting a malicious URL containing the 'column_count' parameter with an XSS payload. When a user clicks on this URL, the payload is executed in their browser, and the attacker can potentially gain access to a user's session or sensitive information.

Here is a simple code snippet demonstrating the vulnerability in action

https://www.example.com/opnsense/index.php?column_count=<script>alert('XSS')</script>;

In this example, the XSS payload is <script>alert('XSS')</script>, which will display a JavaScript alert with the message "XSS" when the exploit is successful.

Mitigation and Solution

The developers of OPNsense have released a fix for this vulnerability in version 23.7.5 and later. To protect yourself from this vulnerability, it is recommended to upgrade your OPNsense installation to the latest version by following the official documentation provided by the developers: Upgrade Guide.

If for some reason you cannot upgrade, be cautious when clicking on links that contain the column_count parameter, and always validate user input to prevent XSS attacks. In addition, you can implement Content-Security-Policy (CSP) headers on your OPNsense installation to mitigate the risk of XSS vulnerabilities.

Original References and Documentation

- CVE Details - CVE-2023-44275
- OPNsense - Firewall and Routing Platform
- Upgrade Guide for OPNsense

This concludes our long read on the details of CVE-2023-44275, a vulnerability that affected earlier versions of OPNsense before 23.7.5 and allowed for XSS attacks via the index.php column_count parameter. Make sure to upgrade your OPNsense installation and follow best security practices to keep your network safe from potential threats. Stay vigilant and always be on the lookout for new vulnerabilities and exploits that can compromise the security of your systems.

Timeline

Published on: 09/28/2023 05:15:00 UTC
Last modified on: 10/02/2023 18:42:00 UTC