Changeset 51107 for trunk/src/wp-includes/widgets/class-wp-widget-rss.php

Timestamp:

06/08/2021 07:34:28 PM (4 years ago)

Author:

jorbin

Message:

Widgets: Prevent infinite loop in PHP8+ if the URL for the widget instance is incorrectly defined

This checks to make sure $link isn't empty before attempting to manipulate it. A simple test to demonstrate this can be seen at ​https://3v4l.org/PgSZg. Unit tests for both what already works and what is fixed by this change.

Props hellofromTonya, dd32, peterwilsoncc.
Fixes #53278.

File:

• trunk/src/wp-includes/widgets/class-wp-widget-rss.php (modified) (2 diffs)

trunk/src/wp-includes/widgets/class-wp-widget-rss.php

@@ -51 +51 @@
 
         $url = ! empty( $instance['url'] ) ? $instance['url'] : '';
-        while ( stristr( $url, 'http' ) !== $url ) {
+        while ( ! empty( $url ) && stristr( $url, 'http' ) !== $url ) {
             $url = substr( $url, 1 );
         }
@@ -75 +75 @@
             }
             $link = strip_tags( $rss->get_permalink() );
-            while ( stristr( $link, 'http' ) !== $link ) {
+            while ( ! empty( $link ) && stristr( $link, 'http' ) !== $link ) {
                 $link = substr( $link, 1 );
             }