|Red Hat Enterprise Linux 4: Introduction to System Administration
|Chapter 1. The Philosophy of System Administration
No matter what you might think about the environment in which your systems are running, you cannot take security for granted. Even standalone systems not connected to the Internet may be at risk (although obviously the risks will be different from a system that has connections to the outside world).
Therefore, it is extremely important to consider the security implications of everything you do. The following list illustrates the different kinds of issues you should consider:
The nature of possible threats to each of the systems under your care
The location, type, and value of the data on those systems
The type and frequency of authorized access to the systems
While you are thinking about security, do not make the mistake of assuming that possible intruders will only attack your systems from outside of your company. Many times the perpetrator is someone within the company. So the next time you walk around the office, look at the people around you and ask yourself this question:
What would happen if that person were to attempt to subvert our security?
This does not mean that you should treat your coworkers as if they are criminals. It just means that you should look at the type of work that each person performs and determine what types of security breaches a person in that position could perpetrate, if they were so inclined.
While most system administrators' first reactions when they think about security is to concentrate on the technological aspects, it is important to maintain perspective. Quite often, security breaches do not have their origins in technology, but in human nature.
People interested in breaching security often use human nature to entirely bypass technological access controls. This is known as social engineering. Here is an example:
The second shift operator receives an outside phone call. The caller claims to be your organization's CFO (the CFO's name and background information was obtained from your organization's website, on the "Management Team" page).
The caller claims to be calling from some place halfway around the world (maybe this part of the story is a complete fabrication, or perhaps your organization's website has a recent press release that makes mention of the CFO attending a tradeshow).
The caller tells a tale of woe; his laptop was stolen at the airport, and he is with an important customer and needs access to the corporate intranet to check on the customer's account status. Would the operator be so kind as to give him the necessary access information?
Do you know what would your operator do? Unless your operator has guidance (in the form of policies and procedures), you very likely do not know for sure.
Like traffic lights, the goal of policies and procedures is to provide unambiguous guidance as to what is and is not appropriate behavior. However, just as with traffic lights, policies and procedures only work if everyone follows them. And there is the crux of the problem — it is unlikely that everyone will adhere to your policies and procedures. In fact, depending on the nature of your organization, it is possible that you do not even have sufficient authority to define policies, much less enforce them. What then?
Unfortunately, there are no easy answers. User education can help; do everything you can to help make your user community aware of security and social engineering. Give lunchtime presentations about security. Post pointers to security-related news articles on your organization's mailing lists. Make yourself available as a sounding board for users' questions about things that do not seem quite right.
In short, get the message out to your users any way you can.