Security bug in latest mavericks

Running mid 2012 macbook pro

In the latest mavericks update there is an error wich can bypass the password set on the mac it is as follows:

I was on an application running at 3/4 of RAM and 5000RPM fans so it was consuming alot of battery, i use it till the battery dies when i opened it again it didnt ask for the password just let me in.

Btw this is not a tutorial to enter someones mac just thought i'll let you all know so this post doesnt get deleted my a mod.

Thanks

A mac user.