Information Disclosure

Drupal core gives us a facility to show error messages to the site's anonymous users or site visitors. By default, this configuration is enabled which is an advantage to the developer during the building of the website because the anonymous user can rapidly see that error message in the browser.

Once the website is going to the Production mode then this configuration should be disabled to keep away from data exposure. For example: If the file URL is not accessible then the file path on the server shows the table structure in the error message 

// Place this in settings.php to disable printing of error messages.

$conf['error_level'] = 0;