Media: Limit thumbnail file deletions to the same directory as the original file.

Merges [43393] into the 4.1 branch.

Built from https://develop.svn.wordpress.org/branches/4.1@43401


git-svn-id: http://core.svn.wordpress.org/branches/4.1@43229 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/functions.php

@@ -1575,18 +1575,38 @@ function path_join( $base, $path ) {
 /**
  * Normalize a filesystem path.
  *
- * Replaces backslashes with forward slashes for Windows systems, and ensures
+ * On windows systems, replaces backslashes with forward slashes
- * no duplicate slashes exist.
+ * and forces upper-case drive letters.
+ * Allows for two leading slashes for Windows network shares, but
+ * ensures that all other duplicate slashes are reduced to a single.
  *
  * @since 3.9.0
+ * @since 4.4.0 Ensures upper-case drive letters on Windows systems.
+ * @since 4.5.0 Allows for Windows network shares.
+ * @since 4.9.7 Allows for PHP file wrappers.
  *
  * @param string $path Path to normalize.
  * @return string Normalized path.
  */
 function wp_normalize_path( $path ) {
+	$wrapper = '';
+	if ( wp_is_stream( $path ) ) {
+		list( $wrapper, $path ) = explode( '://', $path, 2 );
+		$wrapper .= '://';
+	}
+
+	// Standardise all paths to use /
 	$path = str_replace( '\\', '/', $path );
-	$path = preg_replace( '|/+|','/', $path );
+
-	return $path;
+	// Replace multiple slashes down to a singular, allowing for network shares having two slashes.
+	$path = preg_replace( '|(?<=.)/+|', '/', $path );
+
+	// Windows paths should uppercase the drive letter
+	if ( ':' === substr( $path, 1, 1 ) ) {
+		$path = ucfirst( $path );
+	}
+
+	return $wrapper . $path;
 }
 
 /**
@@ -4855,3 +4875,29 @@ function wp_validate_boolean( $var ) {
 
 	return (bool) $var;
 }
+
+/**
+ * Deletes a file if its path is within the given directory.
+ *
+ * @since 4.9.7
+ *
+ * @param string $file      Absolute path to the file to delete.
+ * @param string $directory Absolute path to a directory.
+ * @return bool True on success, false on failure.
+ */
+function wp_delete_file_from_directory( $file, $directory ) {
+	$real_file = realpath( wp_normalize_path( $file ) );
+	$real_directory = realpath( wp_normalize_path( $directory ) );
+
+	if ( false === $real_file || false === $real_directory || strpos( wp_normalize_path( $real_file ), trailingslashit( wp_normalize_path( $real_directory ) ) ) !== 0 ) {
+		return false;
+	}
+
+	/** This filter is documented in wp-admin/custom-header.php */
+	$delete = apply_filters( 'wp_delete_file', $file );
+	if ( ! empty( $delete ) ) {
+		@unlink( $delete );
+	}
+
+	return true;
+}

wp-includes/post.php

@@ -4806,46 +4806,79 @@ function wp_delete_attachment( $post_id, $force_delete = false ) {
 	/** This action is documented in wp-includes/post.php */
 	do_action( 'deleted_post', $post_id );
 
+	wp_delete_attachment_files( $post_id, $meta, $backup_sizes, $file );
+
+	clean_post_cache( $post );
+
+	return $post;
+}
+
+/**
+ * Deletes all files that belong to the given attachment.
+ *
+ * @since 4.9.7
+ *
+ * @param int    $post_id      Attachment ID.
+ * @param array  $meta         The attachment's meta data.
+ * @param array  $backup_sizes The meta data for the attachment's backup images.
+ * @param string $file         Absolute path to the attachment's file.
+ * @return bool True on success, false on failure.
+ */
+function wp_delete_attachment_files( $post_id, $meta, $backup_sizes, $file ) {
+	global $wpdb;
+
 	$uploadpath = wp_upload_dir();
+	$deleted    = true;
 
 	if ( ! empty($meta['thumb']) ) {
 		// Don't delete the thumb if another attachment uses it.
 		if (! $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE meta_key = '_wp_attachment_metadata' AND meta_value LIKE %s AND post_id <> %d", '%' . $wpdb->esc_like( $meta['thumb'] ) . '%', $post_id)) ) {
 			$thumbfile = str_replace(basename($file), $meta['thumb'], $file);
-			/** This filter is documented in wp-admin/custom-header.php */
+			if ( ! empty( $thumbfile ) ) {
-			$thumbfile = apply_filters( 'wp_delete_file', $thumbfile );
+				$thumbfile = path_join( $uploadpath['basedir'], $thumbfile );
-			@ unlink( path_join($uploadpath['basedir'], $thumbfile) );
+				$thumbdir  = path_join( $uploadpath['basedir'], dirname( $file ) );
+
+				if ( ! wp_delete_file_from_directory( $thumbfile, $thumbdir ) ) {
+					$deleted = false;
+				}
+			}
 		}
 	}
 
 	// Remove intermediate and backup images if there are any.
 	if ( isset( $meta['sizes'] ) && is_array( $meta['sizes'] ) ) {
+		$intermediate_dir = path_join( $uploadpath['basedir'], dirname( $file ) );
 		foreach ( $meta['sizes'] as $size => $sizeinfo ) {
 			$intermediate_file = str_replace( basename( $file ), $sizeinfo['file'], $file );
-			/** This filter is documented in wp-admin/custom-header.php */
+			if ( ! empty( $intermediate_file ) ) {
-			$intermediate_file = apply_filters( 'wp_delete_file', $intermediate_file );
+				$intermediate_file = path_join( $uploadpath['basedir'], $intermediate_file );
-			@ unlink( path_join( $uploadpath['basedir'], $intermediate_file ) );
+
+				if ( ! wp_delete_file_from_directory( $intermediate_file, $intermediate_dir ) ) {
+					$deleted = false;
+				}
+			}
 		}
 	}
 
 	if ( is_array($backup_sizes) ) {
+		$del_dir = path_join( $uploadpath['basedir'], dirname( $meta['file'] ) );
 		foreach ( $backup_sizes as $size ) {
 			$del_file = path_join( dirname($meta['file']), $size['file'] );
-			/** This filter is documented in wp-admin/custom-header.php */
+			if ( ! empty( $del_file ) ) {
-			$del_file = apply_filters( 'wp_delete_file', $del_file );
+				$del_file = path_join( $uploadpath['basedir'], $del_file );
-			@ unlink( path_join($uploadpath['basedir'], $del_file) );
+
+				if ( ! wp_delete_file_from_directory( $del_file, $del_dir ) ) {
+					$deleted = false;
+				}
+			}
 		}
 	}
 
-	/** This filter is documented in wp-admin/custom-header.php */
+	if ( ! wp_delete_file_from_directory( $file, $uploadpath['basedir'] ) ) {
-	$file = apply_filters( 'wp_delete_file', $file );
+		$deleted = false;
+	}
 
-	if ( ! empty($file) )
+	return $deleted;
-		@ unlink($file);
-
-	clean_post_cache( $post );
-
-	return $post;
 }
 
 /**