Summary The default HTML editor provider allows unauthenticated file uploads and images can overwrite existing files.

Description An unauthenticated user can upload and replace existing files allowing defacing a website and combined with other issue, injection XSS payloads.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to 9.13.2, when uploading files (e.g. when uploading assets), the file extension is checked to see if it's an allowed file type but the actual contents of the file aren't checked. This means that it's possible to e.g. upload an executable file renamed to be a .jpg. This file could then be executed by another security vulnerability. This vulnerability is fixed in 9.13.2.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Possible denial of service with specially crafted information in the public registration form. This vulnerability is fixed in 9.13.8.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. The algorithm used to generate the captcha image shows the least complexity of the desired image. For this reason, the created image can be easily read by OCR tools, and the intruder can send automatic requests by building a robot and using this tool. This vulnerability is fixed in 9.13.8.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. In limited configurations, registered users may be able to craft a request to enumerate/access some portal files they should not have access to. This vulnerability is fixed in 9.13.8.

Summary Arbitrary themes can be loaded through query parameters. If an installed theme had a vulnerability, even if it was not used on any page, this could be loaded on unsuspecting clients without knowledge of the site owner.

Details Many people who run DNN sites have a number of installed themes that they do not actually use. This could be because they were testing many themes during initial setup, because they have changed themes over time, or because they have development and production versions of a theme. Whatever the reason, many times the unused themes will become outdated over time as site admins wouldn't have reason to update something that is not used. However, this could introduce an entry point to exploit a vulnerable theme by making the server run the unused theme for unsuspecting client requests. Depending on the vulnerability in a theme, this could lead to server side or client side arbitrary code execution. With DNN 10.1.0 this functionality is now disabled by default but a setting was introduced in the Security module to turn activate the functionality.

Summary Sanitization of the content of uploaded SVG files was not covering all possible XSS scenarios.

Details DNN validates the contents of SVG's to ensure they are valid and do not contain any malicious code. These checks were introduced as part of CVE-2025-48378.

However, the checks to ensure there are no script elements within the SVG files are not comprehensive and may allow some malicious SVG files to be uploaded.

As this vulnerability allows for the execution of arbitrary JavaScript code within the context of the user's browser, it can lead to a range of attacks, including data exfiltration, session hijacking, and defacement of the web application to name a few.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 9.13.9, uploaded SVG files could contain scripts and if rendered inline those scripts could run allowing XSS attacks. Version 9.13.9 fixes the issue.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, specially crafted URLs to the FileBrowser are vulnerable to javascript injection, affecting any unsuspecting user clicking such link. This issue has been patched in version 10.1.0.

A specially crafted URL may be constructed which can inject an XSS payload that is triggered by using some module actions.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. Prior to version 10.1.0, the CKEditor file upload endpoint has insufficient sanitization for filenames allowing probing network endpoints. A specially crafted request can be made to upload a file with Unicode characters, which would be translated into a path that could expose resources in the internal network of the hosted site. This issue has been patched in version 10.1.0.

DNN (formerly DotNetNuke) is an open-source web content management platform (CMS) in the Microsoft ecosystem. A url could be crafted to the DNN ImageHandler to render text from a querystring parameter. This text would display in the resulting image and a user that trusts the domain might think that the information is legitimate. This vulnerability is fixed in 9.13.4.

Summary The out-of-box experience for HTML editing allows unauthenticated users to upload files. This opens a potential vector to other security issues and is not needed on most implementations.

Details The new out-of-box experience blocks that endpoint to unauthenticated users. If there is a real need for the implementation to allow unauthenticated uploads, then the web.config can be edited by the implementer to remove that block and open the endpoint to the public.

A malicious SuperUser (Host) could craft a request to use an external url for a site export to then be imported.