Undefined index notice

Hi,

I’m getting an undefined index error on line 45 of stop-user-enumeration.php, which is part of the ll_detect_enumeration() function.

This is happening on requests to a page without the trailing slash, e.g. request to /about-us rather than /about-us/. In this instance, the first preg_match statement is returning false (because ‘author’ is not in the query string) so the second check is running: ($_POST['author']). This is emitting an undefined index notice, because the key ‘author’ does not exist in the $_POST array.

This is in-turn breaking the redirect, because a PHP notice is being emitted before the redirect headers can be sent. Of course this only happens if PHP is configured to output notice messages – typically this means that WP_DEBUG is enabled.

Suggested fix

Replace ($_POST['author']) with isset($_POST['author']) to check whether the author key has been set.

Thanks

https://wordpress.org/plugins/stop-user-enumeration/