在ASP.NET Core的策略授权中，当尝试访问未经授权的操作时，通常会抛出UnauthorizedAccessException异常。然而，有时该异常未被正确处理，从而导致系统崩溃或泄露敏感信息。为解决此问题，可以采用以下步骤：

1.自定义IExceptionHandlerMiddleware

public class CustomExceptionHandlerMiddleware
{
    private readonly RequestDelegate _next;
    private readonly ILogger logger;

    public CustomExceptionHandlerMiddleware(RequestDelegate next, ILoggerFactory loggerFactory)
    {
        _next = next;
        logger = loggerFactory.CreateLogger();
    }

    public async Task InvokeAsync(HttpContext context)
    {
        try
        {
            await _next(context);
        }
        catch (UnauthorizedAccessException ex)
        {
            logger.LogError(ex, "Unauthorized Access Exception");
            context.Response.StatusCode = 403;
        }
        catch (Exception ex)
        {
            // Handle other exceptions...
        }
    }
}

public static class CustomExceptionHandlerMiddlewareExtensions
{
    public static IApplicationBuilder UseCustomExceptionHandler(
        this IApplicationBuilder builder)
    {
        return builder.UseMiddleware();
    }
}

2.在Startup.cs中使用自定义中间件

public void Configure(IApplicationBuilder app, IWebHostEnvironment env, ILogger logger)
{
    if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseHsts();
    }

    app.UseHttpsRedirection();
    app.UseRouting();
    app.UseAuthorization();

    app.UseCustomExceptionHandler(); // Inject the custom middleware for handling unauthorized access.

    app.UseEndpoints(endpoints =>
    {
        endpoints.MapControllers();
    });
}

上述步骤中，我们定义了一个自定义IExceptionHandlerMiddleware，在异常处理程序中捕获UnauthorizedAccessException异常，并记录日志。最后，我们将中间件植入Startup.cs中的管道中，以确保所有未经授权的访问可被正确地处理。