I've searched my FTP for the TimThumb within CORONA, but I haven't found any file concerning this.
Then I used this plugin
to check, whether I have an unsafe TimThumb at my Wordpress - and the plugin found a lot of TimThumb-files of other themes, that I have installed, but nothing within the CORONA theme.
Where is the TimThumb script for CORONA and is it a new, safe version? Where can I check this?