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.
The user interface (UI) does not properly represent critical information to the user, allowing the information - or its source - to be obscured or spoofed. This is often a component in phishing attacks.
If an attacker can cause the UI to display erroneous data, or to otherwise convince the user to display information that appears to come from a trusted source, then the attacker could trick the user into performing the wrong action. This is often a component in phishing attacks, but other kinds of problems exist. For example, if the UI is used to monitor the security state of a system or network, then omitting or obscuring an important indicator could prevent the user from detecting and reacting to a security-critical event. UI misrepresentation can take many forms: