Index: src/wp-admin/css/common.css
===================================================================
--- src/wp-admin/css/common.css	(revision 40572)
+++ src/wp-admin/css/common.css	(working copy)
@@ -2817,6 +2817,10 @@
 	border: 1px solid #ccc;
 }
 
+#plugin-information iframe {
+	max-width: 100%;
+}
+
 /* rtl:ignore */
 #plugin-information .review {
 	overflow: hidden; /* clearfix */
Index: src/wp-admin/includes/plugin-install.php
===================================================================
--- src/wp-admin/includes/plugin-install.php	(revision 40572)
+++ src/wp-admin/includes/plugin-install.php	(working copy)
@@ -482,7 +482,8 @@
 		'div' => array( 'class' => array() ), 'span' => array( 'class' => array() ),
 		'p' => array(), 'ul' => array(), 'ol' => array(), 'li' => array(),
 		'h1' => array(), 'h2' => array(), 'h3' => array(), 'h4' => array(), 'h5' => array(), 'h6' => array(),
-		'img' => array( 'src' => array(), 'class' => array(), 'alt' => array() )
+		'img' => array( 'src' => array(), 'class' => array(), 'alt' => array() ),
+		'iframe' => array( 'src' => true, 'title' => true, 'allowfullscreen' => true, 'class' => true, 'width' => true, 'height' => true, 'type' => true )
 	);
 
 	$plugins_section_titles = array(
@@ -497,7 +498,8 @@
 
 	// Sanitize HTML
 	foreach ( (array) $api->sections as $section_name => $content ) {
-		$api->sections[$section_name] = wp_kses( $content, $plugins_allowedtags );
+		$content = wp_kses( $content, $plugins_allowedtags );
+		$api->sections[ $section_name ] = str_replace( '<iframe', '<iframe sandbox="allow-scripts allow-same-origin" security="restricted"', $content );
 	}
 
 	foreach ( array( 'version', 'author', 'requires', 'tested', 'homepage', 'downloaded', 'slug' ) as $key ) {