include::../description.adoc[]

include::../ask-yourself.adoc[]

include::../recommended.adoc[]

== Sensitive Code Example

PHP built-in header function:

----
header("Access-Control-Allow-Origin: *"); // Sensitive
----

Laravel:

----
response()->header('Access-Control-Allow-Origin', "*"); // Sensitive
----

Symfony:

----
use Symfony\Component\HttpFoundation\Response;

$response = new Response(
    'Content',
    Response::HTTP_OK,
    ['Access-Control-Allow-Origin' => '*'] // Sensitive
);
$response->headers->set('Access-Control-Allow-Origin', '*'); // Sensitive
----

User-controlled origin:

[source,php]
----
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;

$origin = $request->headers->get('Origin');

$response->headers->set('Access-Control-Allow-Origin', $origin); // Sensitive
----

== Compliant Solution

PHP built-in header function:

[source,php]
----
header("Access-Control-Allow-Origin: $trusteddomain"); 
----

Laravel:

[source,php]
----
response()->header('Access-Control-Allow-Origin', $trusteddomain); 
----

Symfony:

[source,php]
----
use Symfony\Component\HttpFoundation\Response;

$response = new Response(
    'Content',
    Response::HTTP_OK,
    ['Access-Control-Allow-Origin' => $trusteddomain]
);

$response->headers->set('Access-Control-Allow-Origin', $trusteddomain); 
----

User-controlled origin validated with an allow-list:

[source,php]
----
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\HttpFoundation\Request;

$origin = $request->headers->get('Origin');

if (in_array($origin, $trustedOrigins)) {
    $response->headers->set('Access-Control-Allow-Origin', $origin); 
}
----

include::../see.adoc[]

ifdef::env-github,rspecator-view[]

'''
== Implementation Specification
(visible only on this page)

include::../message.adoc[]

include::../highlighting.adoc[]

'''
== Comments And Links
(visible only on this page)

include::../comments-and-links.adoc[]

endif::env-github,rspecator-view[]
