What is an attack surface? How can you shrink an attack surface?

What is an attack surface? An attack surface is the total of all the different entry points, otherwise known as attack vectors, that a cybercriminal could utilize to gain access to an organization and carry out a cyberattack.

Once the hacker has entered a network by way of one of these vulnerabilities, they may damage or steal data, infiltrate the entire network, and introduce ransomware or other malware. Reducing your attack surface is critical to keeping your organization secure. The smaller the attack surface, the harder it is for a hacker to gain access.

To reduce an attack surface, you’ll need to analyze and map out exactly what consitutes your attack service, and then monitor it continuously to ensure that any threats are mitigated as fast as possible. You can also implement security strategies that will reduce your attack surface.

What is attack surface analysis?

One of the first steps towards reducing your attack surface is carrying out an attack surface analysis.

Attack surface analysis is the process through which potential vulnerabilities and entry points into a system are identified and evaluated. To do this, an organization must examine the organizational network in its entirety, from its overall structure through to its interfaces, hardware, and applications. This information can be used to calculate the size of the attack surface and how exposed the system is to potential cyber threats.

Carrying out an attack surface analysis may comprise of the following steps:

1. Identify all of the devices and other components in the system, such as software, hardware, and network infrastructure.
2. Create a map of the attack surface, identifying all possible entry points. These may include ports, user interfaces, connections, and external tools.
3. Perform a risk assessment to determine which entry points create the greatest vulnerabilities using various methods such as scans, configuration analysis, and penetration testing.
4. Develop mitigation strategies to overcome the highest risk vulnerabilities. This may include applying patches, performing updates, training users in best practices, or tightening up access controls.
5. Perform attack surface monitoring to ensure the attack surface remains minimized and any new threats are addressed promptly.

What is attack surface monitoring?

Attack surface monitoring is a continuous process by which an organization surveys all of its network and devices to identify any changes to the attack surface. For example, if there are new potential vulnerabilities, attack surface surveillance will pick up on them and allow new mitigations to be put in place to ensure that system security is maintained. To perform attack surface monitoring, an organization may need to carry out some or all of the following activities:

• Monitor new additions to the system, such as new devices, and ensure they are configured to meet best practices and security requirements.
• Carry out regular vulnerability scans to identify new known vulnerabilities in system software, which may be used as attack vectors.
• In 2022 alone, the National Vulnerability Database published over 25,000 different vulnerabilities. Make sure you monitor threat intelligence sources to keep up-to-date with the latest threats that may pose a risk to the system.
• Monitor system logs to identify suspicious behavior that may signify a breach.
• Ensure there are mitigations in place to manage the external attack surface.

What is external attack surface management?

External attack surface management is the process through which external-facing assets, such as web applications, APIs, and cloud services, are managed to ensure vulnerabilities and risks and identified, assessed, and mitigated.

To manage external attack surfaces, an organization should perform some or all of the following steps:

1. Identify all external assets, including any public-facing domains, services, IP addresses, and web applications.
2. Use security tools, code reviews, and penetration testing to identify specific weaknesses in the external assets which could create entry points for cybercriminals.
3. Perform risk analysis for any third-party vendors supplying services that may form part of the external attack surface.
4. Detect and respond to any changes in the external attack surface by applying new mitigations.

Attack surface reduction techniques

In addition to monitoring and management, there are a few strategies that you can use to reduce your attack surface and ensure that your network remains secure:

Adopt a Zero Trust security model

A Zero Trust security model ensures that all network users only have access to the exact resources they need, when they need it. This makes your entire network more secure, and reduces the possible paths through which a cybercriminal could infiltrate your network and gain access to unauthorized data.

Use network segmentation

By splitting your network up into microsegments, as is part of the zero trust security model, you create many, small attack surfaces instead of one large one. This means that even if a microsegment is breached, the attacker has no way to infiltrate other parts of the network, and the damage they can do is greatly limited.

Simplify your infrastructure

Usually, a complex network means many entry points to monitor and manage. Simplifying your network infrastructure makes it easier to see when there’s a potential problem, and decreases the number of entry points. Reduce the number of devices and applications, ensuring anything unnecessary is disabled or removed. This is especially important in recent years, as the number of remote workers has risen, and users often use their own devices that may not be protected adequately.

Ensure secure access

Using a security tool such as ZTEdge can enable you to secure both managed and unmanaged devices in your network, reducing the incidence of stolen credentials, malware, and ensuring everyone has the access rights they ended and nothing else.

Provide training for network users

All network users should be educated in best practices for maintaining network security, such as how to keep passwords safe, how to identify phishing attempts, and when it is and isn’t safe to share data.

Monitor regularly

As mentioned above, running regular scans for system vulnerabilities ensures that you identify weaknesses quickly and implement the needed mitigations before they pose a risk to your network. Keeping abreast of all changes to devices and software is also crucial, so you can make sure they are secure and configured correctly.

Secure access from unmanaged devices

Unmanaged devices represent a dangerous attack surface, regardless of whether they are BYODs that employees use to log in from home, or work devices belonging to 3rd party contractors. A clientless secure access solution is essential to ensure that devices that are not managed by an organization’s IT cannot serve as an entry point for breaches to your network.

Overall, attack surface reduction is key to maintaining network security. By decreasing the number of entry points to your system using strategies, monitoring, and management, you can ensure that your network is always secure and protected against the latest threats.