It's secured by a four digit password and self destruction after three consecutive invalid PIN entries. Which is plenty secure against brute force. Or is that just the way it works around here?
Unfortunately it doesn't prevent them using them online as well. At least for my cards, if I lock out the PIN I can still use them for non-PIN purchases.
Also CVV needs the 16 digit card number, card holder name and expiry as well..
I'd almost guarantee that trying to brute-force a CVV number will get your card blocked real fast.