Enabling ASP.NET (.aspx) support for Apache on Linux using cPanel/WHM
While cPanel/WHM itself does not directly run ASP.NET (.aspx) files, tools are included that allow you to install a third-party component that makes it possible to serve ASP.NET (.aspx) pages via Apache. cPanel/WHM includes a feature called EasyApache, and it is EasyApache that allows you to install a third-party component called "mod_mono" and "mono" that makes it possible for Apache/httpd web server to serve ASP.NET (.aspx) web pages.
I recommend referring to the official Mono protect web site for more detailed information on what is involved and what it can and cannot do: Main Page - Mono
Please note that while ASP.NET (v1 and v2) support is in mod_mono, legacy "ASP" support is not; depending on the specific ASP or ASP.NET functions needed mod_mono may (or may not) serve to fulfill the exact requirements involved. Mono/Mod_mono is an open source project that at best will provide similar functionality to the Windows .NET counterpart but there may be certain areas of it not yet covered, most likely certain newer features or functionality that was only introduced in the later versions of ASP.NET; however, to the best of my knowledge it does have relatively robust support for ASP.NET v1 and most of v2, and for reference, which .NET version (v1 or v2) used can be configured server-wide via the Apache configuration.
EasyApache can be run via your root WHM control panel, or it can be run via root SSH Access, as described below:
Here is the command to run EasyApache via root SSH access:
Here is the menu path to run EasyApache via your root WHM control panel:
WHM: Main >> Software >> EasyApache (Apache Update)