ASP.NET Core 1.0. 1.1, and 2.0 allow an elevation of privilege vulnerability due to how web applications that are created from templates validate web requests, aka "ASP.NET Core Elevation Of Privilege Vulnerability".
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0787
https://github.com/aspnet/Announcements/issues/295