I am looking for a specific content management platform that would display themes for my application. Requirements are as folllows:

• Any user can upload content, but has to be approved by an administrator
• When the user uploads the content, an external application is called to generate a thumbnail

I could create this using codeigniter or something, but I would much prefer to use an existing system. I have experience with Drupal (seems a little bloated for my needs), and Wordpress (I'm using it as main website right now).

Maybe I need a plugin for WordPress instead of another CMS. WordPress currently blocks uploads of my file type. I can modify it, but it's a pain to update it every time WordPress has a new release.