7.4.2 has the same security flaw.
http://www.dnnsoftware.com/community/...2016-06 (Critical) Unauthorized users may create new SuperUser accounts
Published: 5/26/2016
Background
Whilst installing DNN a number of files are used to coordinate the installation of DNN.
Issue Summary
Whilst these files are necessary for installation of DNN, they were left behind after the process finishes. Potential hackers can use a specially crafted URL to access the install wizard and under certain circumstances create an additional host user. As such these files need to be removed to protect against security profiling.
Pre-condition(s)
The files InstallWizard.aspx and InstallWizard.aspx.cs must exist under Website Root\Install folder.
Fix(s) for issue
To fix this problem, you are recommended to update to the latest versions of the Products - DNN Platform 8.0.3 or Evoq 8.4.2 at the time of writing.
As a temporary alternative, the following files under Website Folder\Install should be deleted:
DotNetNuke.install.config
DotNetNuke.install.config.resources
InstallWizard.aspx
InstallWizard.aspx.cs
InstallWizard.aspx.designer.cs
UpgradeWizard.aspx
UpgradeWizard.aspx.cs
UpgradeWizard.aspx.designer.cs
Install.aspx
Install.aspx.cs
Install.aspx.designer.cs
Recommended cleanup steps after breach
Go to Host > Host Settings page > Other Settings section > under Allowable File Extensions > and ensure that the .aspx extension is NOT allowed to be uploadable
Go to Host > SuperUser Accounts page and review the list of users in the Super User section to ensure that only known and authorized users are listed. Remove any unauthorized users.
Search the Root folder and subfolders of your site for any files with .aspx or .php extensions. Some .aspx files might be required for your site. Carefully inspect any files before deleting.
Change SQL Server password and update connection string in the web.config of your DNN application. This is needed only when you are using a username and password in the connection string. It's not needed while using Trusted Connection.