Think back to the beginning of this course when we talked about attacks and vulnerabilities. The special class of vulnerabilities we discussed called zero-day vulnerabilities are unique since they're unknown until they're exploited in the wild. The potential for these unknown flaws is something you should think about when looking to secure your company's systems and networks. Even though it's an unknown risk, it can still be handled by taking measures to restrict and control access to systems. Our end goal overall is risk reduction. Two important terms to know when talking about security risks are attack vectors and attack surfaces. An attack vector is a method or mechanism by which an attacker or malware gains access to a network or system. Some attack vectors are email attachments, network protocols or services, network interfaces, and user input. These are different approaches or paths that an attacker could use to compromise a system if they're able to exploit it. An Attack Surface is the sum of all the different attack vectors in a given system. Think of this as the combination of all possible ways an attacker could interact with our system, regardless of known vulnerabilities. It's not possible to know of all vulnerabilities in the system. So, make sure to think of all avenues that an outside actor could interact with our systems as a potential Attack Surface. The main takeaway here is to keep our Attack Surfaces as small as possible. This reduces the chances of an attacker discovering an unknown flaw and compromising our systems. There are lots of approaches you can use as an IT support specialist to reduce Attack Surfaces. All of them boil down to simplifying systems and services. The less complex something is, the less likely there will be undetected flaws. So, make sure to disable any extra services or protocols. If they're not totally necessary, then get them out of there. Every additional surface that's operating represents additional Attack Surfaces, that could have an undiscovered vulnerability. That vulnerability could be exploited and lead to compromise. This concept also applies to access and ACLs. Only allow access when totally necessary. So, for example, it's probably not necessary for employees to be able to access printers directly from outside of the local network. You can just adjust firewall rules to prevent that type of access. Another way to keep things simple is to reduce your software deployments. Instead of having five different software solutions to accomplish five separate tasks, replace them with one unified solution, if you can. That one solution should require less complex code, which reduces the number of potential vulnerabilities. You should also make sure to disable unnecessary or unused components of software and systems deployed. By disabling features not in use, you're reducing even more tech services, even more. You're not only reducing the number of ways an attacker can get in, but you're also minimizing the amount of code that's active. It's important to take this approach at every level of systems and networks under your administration. It might seem obvious to take these measures on critical networking infrastructure and servers, but it's just as important to do this for desktop and laptop platforms that your employees use. Lots of consumer operating systems ship a bunch of default services and software-enabled right out of the box, that you probably won't be using in an enterprise network or environment. For example, Telnet access for a managed switch has no business being enabled in a real-world environment. You should disable it immediately if you find it on the device. Any vendor-specific API access should also be disabled if you don't plan on using these services or tools. They might be harmless especially if you set up strong firewall rules and network ACLs. This one service might represent a fairly low risk, but why take any unnecessary risk at all? Remember, the defense in depth concept is all about risk mitigation and implementing layers of security. Now, let's think about the layered approach to security. What if our access control measures are bypassed or fail, in some unforeseen way? As an IT support specialist, this is exactly what you want to think about. How do we keep this component secure if the security systems above it have failed?
