From 662033dc1458bbaa1bb3eff94195775fa68a04a3 Mon Sep 17 00:00:00 2001
From: John Blackbourn <johnbillion@git.wordpress.org>
Date: Wed, 29 Nov 2017 16:18:56 +0000
Subject: [PATCH] Hardening: Ensure the attributes of enclosures are correctly
 escaped in RSS and Atom feeds.

Merges [42260] to the 4.7 branch.


git-svn-id: https://develop.svn.wordpress.org/branches/4.7@42274 602fd350-edb4-49c9-b593-d223f7449a82
---
 src/wp-includes/feed.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/wp-includes/feed.php b/src/wp-includes/feed.php
index dbeb3a0f83..a92882f49d 100644
--- a/src/wp-includes/feed.php
+++ b/src/wp-includes/feed.php
@@ -476,7 +476,7 @@ function rss_enclosure() {
 				 *
 				 * @param string $html_link_tag The HTML link tag with a URI and other attributes.
 				 */
-				echo apply_filters( 'rss_enclosure', '<enclosure url="' . trim( htmlspecialchars( $enclosure[0] ) ) . '" length="' . trim( $enclosure[1] ) . '" type="' . $type . '" />' . "\n" );
+				echo apply_filters( 'rss_enclosure', '<enclosure url="' . esc_url( trim( $enclosure[0] ) ) . '" length="' . absint( trim( $enclosure[1] ) ) . '" type="' . esc_attr( $type ) . '" />' . "\n" );
 			}
 		}
 	}
@@ -510,7 +510,7 @@ function atom_enclosure() {
 				 *
 				 * @param string $html_link_tag The HTML link tag with a URI and other attributes.
 				 */
-				echo apply_filters( 'atom_enclosure', '<link href="' . trim( htmlspecialchars( $enclosure[0] ) ) . '" rel="enclosure" length="' . trim( $enclosure[1] ) . '" type="' . trim( $enclosure[2] ) . '" />' . "\n" );
+				echo apply_filters( 'atom_enclosure', '<link href="' . esc_url( trim( $enclosure[0] ) ) . '" rel="enclosure" length="' . absint( trim( $enclosure[1] ) ) . '" type="' . esc_attr( trim( $enclosure[2] ) ) . '" />' . "\n" );
 			}
 		}
 	}