From 68884ef724bc2bf0f2149dd93c3e712cc6329fc9 Mon Sep 17 00:00:00 2001
From: Divyesh Bhandari <79130336+divyeshio@users.noreply.github.com>
Date: Thu, 7 Aug 2025 22:23:18 +0530
Subject: [PATCH 1/4] Update RoutingEndpointConventionBuilderExtensions.cs

---
 .../RoutingEndpointConventionBuilderExtensions.cs  | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
index fbb25d95130f..5eed926c049f 100644
--- a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
+++ b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
@@ -22,6 +22,20 @@ public static class RoutingEndpointConventionBuilderExtensions
     /// An empty collection means any host will be accepted.
     /// </param>
     /// <returns>A reference to this instance after the operation has completed.</returns>
+    /// <remarks>
+    /// APIs that depend on the <see href="https://developer.mozilla.org/docs/Web/HTTP/Headers/Host">Host header</see>, including
+    /// <see cref="HttpRequest.Host"/> and <see cref="RequireHost"/>, are vulnerable to client spoofing.
+    ///
+    /// To safeguard against host and port spoofing:
+    /// <list type="bullet">
+    /// <item><description>
+    /// Verify the server name used during the TLS handshake using <see href="https://learn.microsoft.com/dotnet/api/microsoft.aspnetcore.connections.features.itlshandshakefeature.hostname">ITlsHandshakeFeature.HostName</see>.
+    /// </description></item>
+    /// <item><description>
+    /// Verify the local port where the connection was accepted using <see cref="HttpContext.Connection"/> (specifically <see cref="ConnectionInfo.LocalPort"/>).
+    /// </description></item>
+    /// </list>
+    /// </remarks>
     public static TBuilder RequireHost<TBuilder>(this TBuilder builder, params string[] hosts) where TBuilder : IEndpointConventionBuilder
     {
         ArgumentNullException.ThrowIfNull(builder);

From eca14edf2deb3642a6069268933310ed2ca2fe02 Mon Sep 17 00:00:00 2001
From: Divyesh Bhandari <79130336+divyeshio@users.noreply.github.com>
Date: Thu, 7 Aug 2025 22:54:29 +0530
Subject: [PATCH 2/4] Add using

---
 .../src/Builder/RoutingEndpointConventionBuilderExtensions.cs    | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
index 5eed926c049f..07ea6954ac64 100644
--- a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
+++ b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
@@ -4,6 +4,7 @@
 using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.AspNetCore.Routing;
 using Microsoft.AspNetCore.WebUtilities;
+using Microsoft.AspNetCore.Http;
 
 namespace Microsoft.AspNetCore.Builder;
 

From 3a417d4735b8022453261ac6207531b84a443269 Mon Sep 17 00:00:00 2001
From: Divyesh Bhandari <79130336+divyeshio@users.noreply.github.com>
Date: Fri, 8 Aug 2025 10:37:34 +0530
Subject: [PATCH 3/4] Update
 src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
---
 .../src/Builder/RoutingEndpointConventionBuilderExtensions.cs  | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
index 07ea6954ac64..4d480a5ad48a 100644
--- a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
+++ b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
@@ -5,6 +5,9 @@
 using Microsoft.AspNetCore.Routing;
 using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.AspNetCore.Http;
+using Microsoft.AspNetCore.Http.Metadata;
+using Microsoft.AspNetCore.Routing;
+using Microsoft.AspNetCore.WebUtilities;
 
 namespace Microsoft.AspNetCore.Builder;
 

From 71b08de77ab8707a7333ea1edc8b5cd15eb88c16 Mon Sep 17 00:00:00 2001
From: Divyesh Bhandari <79130336+divyeshio@users.noreply.github.com>
Date: Fri, 8 Aug 2025 15:22:41 +0530
Subject: [PATCH 4/4] Update RoutingEndpointConventionBuilderExtensions.cs

---
 .../src/Builder/RoutingEndpointConventionBuilderExtensions.cs  | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
index 4d480a5ad48a..3820785250ab 100644
--- a/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
+++ b/src/Http/Routing/src/Builder/RoutingEndpointConventionBuilderExtensions.cs
@@ -1,9 +1,6 @@
 // Licensed to the .NET Foundation under one or more agreements.
 // The .NET Foundation licenses this file to you under the MIT license.
 
-using Microsoft.AspNetCore.Http.Metadata;
-using Microsoft.AspNetCore.Routing;
-using Microsoft.AspNetCore.WebUtilities;
 using Microsoft.AspNetCore.Http;
 using Microsoft.AspNetCore.Http.Metadata;
 using Microsoft.AspNetCore.Routing;