A bug in includes/functions.php will cause all lookups to succeed if a domain with a wildcard (*.serverdomain.com) is configured as the default/search domain in the operating system configuration.

As a result, a lookup for userdomain.com will return successful, as userdomain.com.serverdomain.com would be valid due to the wildcard. The wildcard configuration is not uncommon.

This can be fixed easily without harm by suffixing a period (dot) to the end of the host as in the below code-snippet. Adding this dot ignores any default lookup domain.

1. 1. 1. includes/functions.php ###

else if (function_exists('checkdnsrr'))

{ return (checkdnsrr($host.'.', $type)) ? true : false; }