The problem solved with this patch was the DoS or Denial of Service that an attacker could use.

But what is DoS? It means that a user or organizations is deprived of its resources. This means you can lose access to e-mail, you can lose access to the Internet, etc.

In the worst cases, for example, a Web site accessed by millions of people can occasionally be forced to temporarily cease operation. A denial of service attack can also destroy programming and files in a computer system. Although usually intentional and malicious, a denial of service attack can sometimes happen accidentally.

A denial of service attack is a type of security breach to a computer system that does not usually result in the theft of information or other security loss. However, these attacks can cost the target person or company a great deal of time and money. You can find out more about DoS on [1] WiKi.

They still seem to have problems with extensions, memory leaks which were reported by some users. If you’re interested about the update changes you can find them [2] here.