diff --git a/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.cpp b/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.cpp
new file mode 100644
index 00000000000..b608ea133de
--- /dev/null
+++ b/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.cpp
@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2022, Linus Groh <linusg@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <AK/Variant.h>
+#include <AK/Vector.h>
+#include <LibJS/Runtime/Object.h>
+#include <LibWeb/Bindings/CrossOriginAbstractOperations.h>
+#include <LibWeb/Bindings/LocationObject.h>
+#include <LibWeb/Bindings/WindowObject.h>
+
+namespace Web::Bindings {
+
+// 7.2.3.1 CrossOriginProperties ( O ), https://html.spec.whatwg.org/multipage/browsers.html#crossoriginproperties-(-o-)
+Vector<CrossOriginProperty> cross_origin_properties(Variant<LocationObject const*, WindowObject const*> const& object)
+{
+    // 1. Assert: O is a Location or Window object.
+
+    return object.visit(
+        // 2. If O is a Location object, then return « { [[Property]]: "href", [[NeedsGet]]: false, [[NeedsSet]]: true }, { [[Property]]: "replace" } ».
+        [](LocationObject const*) -> Vector<CrossOriginProperty> {
+            return {
+                { .property = "href"sv, .needs_get = false, .needs_set = true },
+                { .property = "replace"sv },
+            };
+        },
+        // 3. Return « { [[Property]]: "window", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "self", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "location", [[NeedsGet]]: true, [[NeedsSet]]: true }, { [[Property]]: "close" }, { [[Property]]: "closed", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "focus" }, { [[Property]]: "blur" }, { [[Property]]: "frames", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "length", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "top", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "opener", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "parent", [[NeedsGet]]: true, [[NeedsSet]]: false }, { [[Property]]: "postMessage" } ».
+        [](WindowObject const*) -> Vector<CrossOriginProperty> {
+            return {
+                { .property = "window"sv, .needs_get = true, .needs_set = false },
+                { .property = "self"sv, .needs_get = true, .needs_set = false },
+                { .property = "location"sv, .needs_get = true, .needs_set = true },
+                { .property = "close"sv },
+                { .property = "closed"sv, .needs_get = true, .needs_set = false },
+                { .property = "focus"sv },
+                { .property = "blur"sv },
+                { .property = "frames"sv, .needs_get = true, .needs_set = false },
+                { .property = "length"sv, .needs_get = true, .needs_set = false },
+                { .property = "top"sv, .needs_get = true, .needs_set = false },
+                { .property = "opener"sv, .needs_get = true, .needs_set = false },
+                { .property = "parent"sv, .needs_get = true, .needs_set = false },
+                { .property = "postMessage"sv },
+            };
+        });
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.h b/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.h
index 945296ae9bc..ba2c1c9cc67 100644
--- a/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.h
+++ b/Userland/Libraries/LibWeb/Bindings/CrossOriginAbstractOperations.h
@@ -9,9 +9,16 @@
 #include <AK/Forward.h>
 #include <AK/Traits.h>
 #include <LibJS/Forward.h>
+#include <LibWeb/Forward.h>
 
 namespace Web::Bindings {
 
+struct CrossOriginProperty {
+    String property;
+    Optional<bool> needs_get {};
+    Optional<bool> needs_set {};
+};
+
 struct CrossOriginKey {
     FlatPtr current_settings_object;
     FlatPtr relevant_settings_object;
@@ -20,6 +27,8 @@ struct CrossOriginKey {
 
 using CrossOriginPropertyDescriptorMap = HashMap<CrossOriginKey, JS::PropertyDescriptor>;
 
+Vector<CrossOriginProperty> cross_origin_properties(Variant<LocationObject const*, WindowObject const*> const&);
+
 }
 
 namespace AK {
diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index c14edb84cb9..c106bf150da 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -1,5 +1,6 @@
 set(SOURCES
     Bindings/AudioConstructor.cpp
+    Bindings/CrossOriginAbstractOperations.cpp
     Bindings/CSSNamespace.cpp
     Bindings/CSSRuleWrapperFactory.cpp
     Bindings/CSSStyleDeclarationWrapperCustom.cpp