Is it possible to disable authorization on one action in an MVC controller?

You can add [Authorize] To the controller class, and then add [AllowAnonymous] to the single action you don’t want to be authorized. Example:

[Authorize]
public class AccountController : Controller
{
    public ActionResult Profile()
    {
        return View();
    }

    [AllowAnonymous]
    public ActionResult Login()
    {
        return View();
    }
}