I'm trying to create a front-end AJAX file uploader for a form and everything is working perfect, except for one issue. I used deferred binding to enable uploading before the record is created in DB. In a rare scenario, when someone uploads a file and doesn't send the form the record is not created, but the attached file still exists. I don't know if there is a build-in solution for this problem is October CMS. A better example is RainLab Blog Plugin. If you try a new post and add a featured image but not save the post and close the tab, the post doesn't create but the file remains in storage/app/uploads/public. I was thinking of writing an scheduled task to delete unbinded files, but don't know how to detect them. Does anyone have a solution for this issue?

Sure, there is already a plugin that does exactly this: http://octobercms.com/plugin/genius-storageclear

Thank you @alxy. I didn't notice this plugin before. It fits my needs perfectly.