Progress Telerik Report Server XmlSerializer NET Deserialization Vulnerability Remote Code Execution Webapp Exploit

This module chains 2 vulnerabilities to deploy an agent in Progress Telerik Report Server that will run with root user privileges. The first vulnerability is an authentication bypass vulnerability present in Telerik.ReportServer.Web.Controllers.StartupController.Register class. The second vulnerability a .NET deserialization vulnerability in Telerik.Reporting.XmlSerialization.XmlSerializer class. This module will use first vulnerability to create a random user with "System Administrator" role against the "/Startup/Register" endpoint and then login into the application. Then, a report with our payload will be uploaded via the "/api/reportserver/report" endpoint. Finally, the second vulnerability will be used to deploy an agent using the "/api/reports/clients" and "/api/reports/clients/clientID/parameters" endpoints. The deployed agent will run with the privileges of the "w3wp" process (TelerikReportServer instance - NT AUTHORITY\\SYSTEM).