DNN Arbitrary Theme Loading Vulnerability Allowing Exploitation of Vulnerable Themes

A vulnerability in DNN (DotNetNuke) prior to version 10.1.0 allows arbitrary themes to be loaded through query parameters. This could lead to exploitation if an outdated or vulnerable theme was installed, potentially allowing for server-side or client-side code execution. The issue arises because unused themes can be overlooked by site administrators, creating a vector for attacks without the owner's knowledge.

Impact

Exploitation of this vulnerability could result in arbitrary code execution, either on the server or client side, depending on the nature of the vulnerability within the loaded theme.

Reproduction

To reproduce this vulnerability, upload a malicious theme to a DNN site that is prior to version 10.1.0. Ensure that the theme is not active on any pages. Then, send a request to the site with a query parameter that includes the name of the uploaded theme. The server will process the request and load the theme, potentially executing any malicious code it contains.

Remediation

Users can update to DNN version 10.1.0 or later, where this vulnerability has been patched. Instructions for updating DNN can be found in the DNN documentation.