If you are responsible for a Debian or Ubuntu server and run PHP on it, make sure to run the following command to fix several security issues found in PHP:
sudo apt-get install php5-suhosin
This will make the necessary and your PHP version (security wise) will look like you have PHP 5.3.3.
What I found quite annoying in regard to this issue is the fact that it was very difficult to find a mention of this upgrade. All I could find in large number were people saying that you'd have to get an upgrade using the source code of PHP. Somehow, I did not feel like upgrading PHP from source!