Hello,

When I upload a picture using the K2 Image tab, the picture that gets uploaded only gets read and write permissions.

Permissions:


Cache dir permissions:
drwxr-xr-x 2 xx xx 32K Apr 18 17:23 cache

Everything in K2 Information is marked as "writable"

Anyone got any idea of why this occurs?

You should install Admin Tools and fix your permissions.
The correct permissions should be 755 for most folders and 644 for files (you might need to double check that).

If that doesn't do the trick you might have to ask your hosting provider for assistance.