PPC (Belden) ONT 2K05X Router Stored Cross-Site Scripting Vulnerability

A stored cross-site scripting vulnerability has been identified in the web management interface of the PPC (Belden) ONT 2K05X router, specifically in firmware version 1.1.9_206L. This vulnerability arises in the Common Gateway Interface (CGI) component, which fails to properly sanitize user input. As a result, a remote, unauthenticated attacker can inject arbitrary JavaScript that is persistently stored and executed when the management interface is accessed.

Impact

Exploitation of this vulnerability allows for stored cross-site scripting, where injected scripts are executed in the context of the user accessing the management interface.

Reproduction

To reproduce this vulnerability, send a crafted HTTP request to the web management interface with a modified 'browserLang' parameter. The backend will store the injected value. Then, access the management interface using a web browser to observe that the stored 'browserLang' value is rendered and executed as JavaScript in the browser context.

Remediation

It is recommended to implement proper input validation and output encoding in the CGI component to prevent the injection of malicious scripts. User-supplied input should be sanitized before being stored and rendered.