Security

In this article you can find information about security on Umbraco Cloud.

HTTPS & Certificates

All Umbraco Cloud websites use HTTPS by default. Both the default {projectName}.{region}.umbraco.io and custom domains are protected by periodically renewed certificates issued by Cloudflare. This service is offered as part of Umbraco Cloud for all plans.

Custom Certificates

Custom certificates can be used with all custom domains. Please refer to our Managing Custom Certificates documentation.

TLS support

As of April 2020, we've deprecated support for TLS 1.0 & TLS 1.1.

TLS 1.2 is now the default supported TLS protocol going forward.

On the Security page for your cloud project, you can change the default settings for both TLS and HTTP.

Learn more about how this in the Manage Security article.

TLS Ciphers support

Umbraco Cloud Websites support the following TLS ciphers in this order:

• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384

• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256

• TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA

• TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA

• TLS_DHE_RSA_WITH_AES_256_GCM_SHA384

• TLS_DHE_RSA_WITH_AES_128_GCM_SHA256

• TLS_DHE_RSA_WITH_AES_256_CBC_SHA

• TLS_DHE_RSA_WITH_AES_128_CBC_SHA

The different Ciphers can be enabled or disabled on the security project settings page for your Cloud projects.

Enable or disable TLS Ciphers

HSTS - HTTP Strict Transport Security

It's possible to enforce HSTS: HTTP Strict Transport Security by adding the headers to your website. This grants Umbraco Cloud Websites an A+ security rating on sslabs (March 2020).

You can add the header by modifying system.webServer/rewrite/outboundRules section in your web.config:

 <outboundRules>
  <rule name="Add Strict-Transport-Security when HTTPS" enabled="true">
  <match serverVariable="RESPONSE_Strict_Transport_Security" pattern=".*" />
  <conditions>
   <add input="{HTTPS}" pattern="on" ignoreCase="true" />
   <add input="{HTTP_HOST}" pattern="localhost" negate="true" />
  </conditions>
  <action type="Rewrite" value="max-age=63072000; includeSubDomains; preload" />
  </rule>
 </outboundRules>

Alternatively this can be done in Startup.cs inside of the ConfigureServices method with the following C#:

public void ConfigureServices(IServiceCollection services)
        {
            services.AddUmbraco(_env, _config)
                .AddBackOffice()
                .AddWebsite()
                .AddComposers()
                .Build();

            services.AddHsts(options =>
            {
                options.MaxAge = TimeSpan.FromDays(730);
                options.IncludeSubDomains = true;
                options.Preload = true;
            });
        }

This adds the "Strict-Transport-Security" header telling browsers how long the browser should not make any HTTP requests to this domain. In this example 63072000 seconds or 730 days is two years.

TLS 1.2 by default in external services

In order to integrate older external applications to access Umbraco Cloud Websites you might have to modify the TLS support in the .Net application.

For ASP.NET applications, inspect the <system.web><httpRuntime targetFramework> element of web.config to find the version of the .NET Framework your application is using. .NET applications on .NET 4.7+ are using the OS specified TLS protocols. In Windows 8 & 10, Windows Server 2012 & 2016 TLS 1.2+ is used by default, therefore no actions necessary. .NET applications lower then 4.7 require updates to ensure they can communicate using TLS 1.2 by default.

More information specifically from Microsoft about .Net applications and Transport Layer Security (TLS) support can be found in Microsoft's official docs. For other application frameworks/languages we encourage to lookup their respective documentations.

HTTP

Naked HTTP urls without HTTPS are supported but not used by default on Umbraco Cloud Websites. If you'd like to keep using HTTP, which we strongly discourage, you'll need to remove a web.config transform as specified in Rewrite rules on Umbraco Cloud

Umbraco Cloud supports both HTTP2 and HTTP3 protocols.

Ports

By default, all ports are closed to secure them against external attacks. This is done for all ports apart from 80 (HTTP) and 443 (HTTPS).

Firewall & Restricting public access to Umbraco Cloud resources

Umbraco Cloud offers a multitude of features allowing you to block access to different resources.

• Basic Authentication allows access to the Backoffice & Frontend of Umbraco Cloud Websites for authenticated users only.

Basic authentication will not be available for projects running Umbraco 9. It is available for Umbraco Cloud version 10 (and newer) versions, however, the users are currently unable to exclude IP addresses for authentication using the allowlist feature.

• IP based list allowing access to Frontend & Backoffice

• IP based list allowing access to website database

Cookies and security

On Umbraco Cloud sites, you will find an ARRAffinity cookie. This is not sent over HTTPS, and might to some, look like a security risk.

It is not a security risk. This cookie is set by the load balancer (LB) and only used by the LB to track which server your site is on. It is set by the software we use (Azure App Service) and only useful when your website is being scaled to multiple servers. In Umbraco Cloud we cannot scale your site to multiple servers so the cookie is effectively unused.

There is no vulnerable data in this cookie and manipulating or stealing this cookie can not lead to any security issues.

In the future, the cookie will be set to HttpOnly on Umbraco Cloud to conform to best practices. This does not mean that there's anything wrong with the current way it is set.

For more information see the related GitHub issue.

Deny specific IPs from accessing your website

You can block people and bots(e.g. a malicious scanning bot) from accessing your website by adding their IP addresses to a deny-list.

The following rule can be added to your web.config file in the system.webServer/rewrite/rules/ section.

<rule name="RequestBlockByIP" patternSyntax="Wildcard" stopProcessing="true">
    <match url="*"/>
    <conditions>
    <add input="{HTTP_CF_Connecting_IP}" negate="false" pattern="123.123.123.123"/>
    </conditions>
    <action type="AbortRequest"/>
</rule>

For anyone using the 123.123.123.123 IP, this will result in them getting a 502 error. You can choose your own error.