I am testing an image uploader but I'm a mere developer.  Here are the main points to consider:

- There are no extension checks.
- The image is uploaded to memory. 
- It is modified to be a certain size (50px x 50px).
- It is saved to the database.
- From testing, it seems if the image size failed, then on re-render the image displayed is simply broken
- The app is asp.net and is on a Windows server.

With the exception of dodgy file name changing in Linux, is there a weakness? Can anything be executed if it's saved to the DB?  I will suggest whitelisting extensions and content type, but is it necessary?  If possible please provide a very basic (safe!) example of any major issues.