A critical missing authorization vulnerability, tracked as CVE-2023-45658, has been discovered in the popular content management system (CMS) POSIMYTH Nexter. The vulnerability affects Nexter users running versions from n/a to 2..3. Attackers who exploit this vulnerability gain unauthorized access to sensitive data and can perform administrative functions that are typically restricted to authorized users.

This post will provide a detailed analysis of the vulnerability, sample code snippets, and useful links for further reference. We strongly recommend affected users to update their installations to the latest secure version.

Vulnerability Details

The missing authorization vulnerability in POSIMYTH Nexter allows an attacker to bypass normal access control measures and access sensitive information or execute restricted actions on the targeted system. The issue arises from inadequate access controls that can be circumvented by sending manipulated requests to the web application.

POSIMYTH Nexter Content Management System (CMS)

- Versions n/a through 2..3

Impact

If exploited, unauthorized users can perform actions such as adding, editing or deleting content, modifying user roles, and even hijacking admin accounts. This can lead to a significant loss of sensitive data and potentially compromise the integrity and security of the entire system.

Exploit

To exploit this vulnerability, an attacker can send a specially crafted HTTP request to the target application. Below is an example of a modified HTTP request that bypasses access control measures:

GET /nexter/admin/edit-content.php?id=1337 HTTP/1.1
Host: target.example.com
User-Agent: Mozilla/5. (Windows NT 10.; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/73..3683.103 Safari/537.36
Cookie: <valid non-admin user session cookie>
Connection: close

In this example, the attacker sends an HTTP GET request to the 'edit-content.php' page with a specified content id (1337). The inclusion of a valid non-admin user session cookie allows the request to be processed without any authorization checks, resulting in unauthorized access.

Mitigation

To protect your Nexter installation against this vulnerability, we recommend updating to the latest version, which includes security patches for this issue. If updating is not possible, consider implementing additional access control measures, such as limiting access to sensitive pages based on IP addresses or other authentication methods.

References

1. MITRE CVE-2023-45658 Details
2. POSIMYTH Nexter Official Website
3. POSIMYTH Nexter Changelog

Conclusion

CVE-2023-45658 highlights the importance of proper access control implementation in web applications. Failing to protect sensitive data and restricting access to authorized users exposes an application to significant risks. To protect your Nexter installation, update to the latest secure version and ensure that proper access control measures are in place.

Timeline

Published on: 06/19/2024 12:15:10 UTC
Last modified on: 06/20/2024 15:53:59 UTC