For v8 sites

gistfile1.txt

using System.Web.Routing;
using Umbraco.Core.Composing;
using Umbraco.Web.Runtime;

namespace RemoveRoutes
{
    // This is required to ensure this composer runs after
    // Umbraco's WebFinalComposer which is the component
    // that creates all of the routes during startup    
    [ComposeAfter(typeof(WebFinalComposer))]
    public class RemoveRoutesComposer : ComponentComposer<RemoveRoutesComponent>
    {
    }

    //The component that runs after WebFinalComponent
    //during startup to modify the routes
    public class RemoveRoutesComponent : IComponent
    {
        public void Initialize()
        {
            // Reference: https://github.com/umbraco/Umbraco-CMS/issues/5206
            // Reference: https://shazwazza.com/post/need-to-remove-an-auto-routed-controller-in-umbraco/
            
            // Note: RouteTable needs System.Web.dll
            RouteTable.Routes.Remove(RouteTable.Routes["umbraco-surface-UmbRegister"]);
            RouteTable.Routes.Remove(RouteTable.Routes["umbraco-surface-UmbProfile"]);
            RouteTable.Routes.Remove(RouteTable.Routes["umbraco-surface-UmbLogin"]);
            RouteTable.Routes.Remove(RouteTable.Routes["umbraco-surface-UmbLoginStatus"]);
            RouteTable.Routes.Remove(RouteTable.Routes["umbraco-api-Tags"]);
        }

        public void Terminate()
        {
        }
    }
}

Please note that we have just updated this code and posted a new security advisory.

Note: As per the comment here, the Tags route was just updated to be umbraco-api-Tags: https://gist.github.com/nul800sebastiaan/927dcf155439fcc867e97a4d8dda6e16#gistcomment-2984807

Hi,
When i add the fix to sites running 8.0.0 i get the following error:

Description: An error occurred during the compilation of a resource required to service this request. Please review the following specific error details and modify your source code appropriately.

Compiler Error Message: CS0246: The type or namespace name 'WebFinalComposer' could not be found (are you missing a using directive or an assembly reference?)

Source Error:

Line 8: // Umbraco's WebFinalComposer which is the component
Line 9: // that creates all of the routes during startup
Line 10: [ComposeAfter(typeof(WebFinalComposer))]
Line 11: public class RemoveRoutesComposer : ComponentComposer
Line 12: {

It OK in later versions.
Any ideas?

Cheers,
Mark