What is an attack surface and how can you reduce it?

In cybersecurity, the term “attack surface” refers to every possible weak spot in your network that could open the door for attackers and jeopardize your system's security and privacy. It's easy to think that your IT department and sysadmins are responsible for vulnerability management. The reality is it's everyone's responsibility — from HR and marketing to sales and creatives. Read the article to learn about the types of attack surface and how to manage and reduce it.

What is an attack surface?

An attack surface is all the vulnerabilities, possible entry points, or attack vectors that hackers can use to infiltrate a system or network and steal private information. The larger and more open the attack surface area, the easier it is for an attacker to penetrate and compromise a system. Therefore, organizations must understand their network's attack surface, address its weakest points, patch it, and minimize the risk of successful cyberattacks.

What are the types of attack surfaces?

Cybersecurity experts distinguish three attack surface categories, including digital, physical, and social engineering attack surfaces.

Digital attack surface

A digital attack surface is the organization's hardware and software that an attacker can reach via an internet connection. The more apps, computers, smartphones, or even smart fridges the company uses, the bigger the digital attack surface grows. Each connection, login, and app creates a new "door" for a cybercriminal to get in through. The most common digital attack vectors include:

• Shadow IT. Shadow IT is software and apps that employees use without telling the IT team. For example, a simple app to help with productivity might seem harmless, but it could become an entry point for hackers if no one's keeping an eye on it.
• Weak passwords. We all know this one. Passwords like "12345" or "letmein" barely protect any account. They are easily guessable or can be cracked using brute force attacks. You need complex and unique passwords to protect access to the network and prevent infrastructure damage and various types of data breaches.
• Unsecured APIs. An API is a set of protocols that allows two software programs to communicate with each other. If the tunnel between the two is not properly locked down, it might become an entry point for hackers.
• Outdated apps and software. Old versions of apps and software have known vulnerabilities that hackers love to exploit for login credentials and confidential information. Remember the WannaCry ransomware? It got into the UK's NHS through unpatched Windows operating systems, locking up files and demanding ransom for the key. It was a costly lesson in why keeping your software up to date is crucial.
• Coding errors. No IT developer is perfect, but even a tiny mistake in the code can give hackers the opening they need to infiltrate a system, bypass security checks, and expose private information.
• Misconfiguration. Misconfigured network ports, channels, protocols, wireless access points, or firewalls open pathways for hackers to sneak in. Packet sniffing attacks, for example, exploit wireless access points by monitoring and capturing unencrypted data packets traveling over the network.

Physical attack surface

Strong passwords, regular software updates, or pristine configuration of your network won't protect your company from cybercriminals if a user loses their laptop, USB, or smartphone. If a hacker gets physical access to a company device, they can access all its sensitive data. The most common physical attack vectors are:

• Stolen devices. Losing a laptop or USB isn't just an inconvenience. If a device with confidential data gets into the wrong hands and those devices are not encrypted — brace yourself. A stranger can access information and processes stored on that device and use the data to access other network resources.
• Improperly discarded hardware. Tossing out computers, hard drives, or phones without wiping them clean can expose their contents to anyone who picks them up.
• Passwords written on paper. Your work email password on a sticky note on your monitor might seem convenient. However, it's a severe cybersecurity hazard — you may never know who sees your little cheat sheet and what they might do with your login credentials.

Social engineering attack surface

Social engineering attacks happen when hackers manipulate people or use trickery instead of cracking and hacking systems. Phishing is the best-known social engineering technique, where attackers send trustworthy-looking emails, texts, or voice messages. Their goal is to get people to click on malicious links, download malware, or hand over personal information. Sometimes they even pose as tech support to get people to share sensitive details. These scams are all about catching you off guard, so staying alert can save you from trouble.

What is attack surface management?

Attack surface management (ASM) is a set of processes where the company's cybersecurity risk team takes the hacker's view and tests the attack surface of a network. The goal is to monitor system vulnerabilities that hackers could detect and exploit. The ASM process includes:

• Continuous monitoring of potential system vulnerabilities.
• Analyzing the attack surface, assessing vulnerabilities, and prioritizing risks.
• Minimizing the attack surface and fixing vulnerabilities.

Threat exposure management platforms like NordStellar are created for this purpose. NordStellar detects loopholes in your organization's network's attack surface and responds to them before hackers do. Its goal is to secure corporate data, prevent account takeover attempts, monitor for data breaches, and stop unauthorized access to your internal systems by detecting stolen employee credentials.

Attack surface vs. attack vector

The attack surface comprises all the possible entry points that attackers could use to break in, like open ports or outdated software. Attack vectors, on the other hand, are the tricks attackers use to get into systems, like phishing emails, malware, or drive-by downloads.

How to define the attack surface area

When defining the attack surface area, your main task is to assess every potential weakness and vulnerability that an attacker could target. Start by listing devices, apps, data storage, web servers, APIs, databases, firewalls, and physical devices connected to your network that your organization relies on. They all count when it comes to keeping the attack surface under control.

Also, don't forget the human error factor, which includes weak passwords or misconfigurations — these could easily become an entry point for an attacker.

Another critical step is to review the storage locations of the corporate data. Make sure all the data is kept separate. This way, even if the attacker does get in, they will not access everything in one go. System administrators can then decide who gets access to what and at what level.

Mapping and defining the attack surface gives you the full picture of how someone could gain unauthorized access to an internal system. Once you've got that, you can prioritize which areas need attention most.

How to reduce the attack surface

Reducing the attack surface requires both the company's and employees' effort. Follow the tips below to minimize your attack surface:

• Educate your employees. Knowledge is key. Teach your employees to spot phishing emails, use strong passwords, and detect suspicious activities on a corporate network or premises.
• Apply a zero-trust security strategy. Only give access to those who truly need it. The zero-trust security model ensures only the right people can access parts of a network. This strengthens the whole network infrastructure and reduces the chances of unauthorized access.
• Implement network segmentation. Break your network into smaller sections so it's easier to block attackers from accessing other segments of your network if someone breaks in.
• Scan for vulnerabilities. Regularly scan your systems for weaknesses before an attacker finds and exploits them.
• Set up two-factor authentication (2FA). Obligate your employees to set up 2FA on their work-related accounts to add an extra layer of security. Sometimes, a password alone is not enough — the further the attacker has to go to access private information, the better.
• Deactivate unused apps and software. Deleting or deactivating unused apps and software is a good cyber hygiene habit. Have as few entries on your attack surface map as possible to minimize the risk of someone using them to gain unauthorized access.

FAQ

What is the difference between an attack surface and a threat?

An attack surface is a sum of all potential entry points that an attacker could exploit. Meanwhile, a threat is anything that could harm your system or data. In other words, the attack surface is what an attacker could target, while a threat is what could exploit those targets.

What is the difference between an attack tree and an attack surface?

An attack surface is a set of various network vulnerabilities and weaknesses that hackers can exploit to gain unauthorized access to private information. An attack tree, on the other hand, is a diagram that outlines the attack paths someone could take to exploit those vulnerabilities and weaknesses.

How do you measure the attack surface?

An attack surface is measured by identifying and analyzing possible organizational threats. The process requires a thorough analysis of the system's entry points, a well-thought-out list of security measures, and how a successful attack could impact the organization.