Successfully securing a computer network is no easy task. But according to Forrester Research the biggest network vulnerabilities come from simple things that we often overlook, rather than from intricately skilled hackers.

“A successful attack depends on a combination of four things that don't have a lot to do with the attacker,” says Forrester's Paul Stamp. “It's usually a combination of two or more of those four factors.”

So what are these four simple security dangers?

Social Engineering: With all the warnings about protecting passwords and not falling for phishing scams, people are still getting duped into giving out personal details. Phising occurs when a perpetrator sends out a legitimate-looking email that appears to come from trustworthy website in an attempt to gather personal and financial information from the recipient. Educating employees about phising scams is absolutely essential.

Process Errors: If companies are going to use networks, wireless and mobile devices, they need to have a way of dealing with everything from absent-mindedness, to incompetence and malice. Without a proper contingency plan, something as simple as forgetting a mobile device in a cab can turn into disaster.

Technical Vulnerabilities: With multiple routers, switches and access points, the likelihood of having network security problems increases exponentially. If there's something that hasn't been configured properly or patched, it makes the entire network vulnerable. Your network is only as strong as its weakest point.

Inside Abuse: The Computer Security Institute/FBI found that every year for the past five years at least half of all security breaches originated on the inside. Many businesses sweep this issue under the carpet as no one wants to believe that one of their own could be the problem.

Fear not. These common dangers can be dealt with quite easily. Stamp suggests that increasing security only takes the will to clean up processes, patch systems and make sure users are doing what they are supposed to be doing.