Oracle has been under pressure to address gaping security vulnerabilities and configuration weaknesses in its Java Runtime Environment, which has become the most widely exploited software platform on the Internet. In addition to revamping its internal incident response and software patching procedures, the software giant has introduced restrictions and stronger certificate validation processes, making it more difficult for an attacker to target a vulnerability. Security experts are embracing the changes, but they say Oracle needs to implement stronger sandboxing. A stronger Java applet container would prevent malicious code from escaping and allowing an attacker access to a victim's machine. But, the security improvements are still significant. Here are the five biggest changes to the platform.