What is Attack Surface ?

The attack surface refers to all the vulnerabilities and entry points that could be exploited by unauthorized users within a given environment. It encompasses both digital and physical components that attackers target to gain unauthorized access.

The digital attack surface includes network interfaces, software, hardware, data, and users. Network interfaces like Wi-Fi and Bluetooth are common targets. Vulnerable software and firmware provide opportunities for injection or buffer overflow attacks. Compromised user credentials and accounts are frequently used to gain access to the system, social engineering attacks.

The physical attack surface refers to the tangible components that can be tampered with to infiltrate a system. This includes unattended workstations, improperly secured server racks, vulnerable wiring, and insecure building access. Attackers may install keylogging devices, steal data storage devices, or gain access to networks by bypassing physical security controls.

What vulnerabilities constitute an attack surface?

A system’s attack surface consists of any weaknesses or flaws that can be exploited to gain unauthorized access to data. Potential vulnerabilities include:

  • Software and hardware components
  • Network infrastructure
  • User access and credentials
  • System configurations
  • Physical security

Attack Vector vs Attack Surface

Attack vectors describe the path or means by which an attacker can gain access to a system, such as through malware, phishing emails, USB drives, or software vulnerabilities. Attack surface is the number of possible attack vectors that can be used to attack a system.

Reducing the attack surface requires identifying and eliminating as many vulnerabilities as possible across all potential attack vectors. This can be achieved through measures like patching software, restricting user permissions, disabling unused ports or services, implementing multi-factor authentication (MFA), and deploying updated antivirus or anti-malware solutions.

An optimized attack surface not only strengthens security posture but also allows cybersecurity teams to focus resources on monitoring and protecting critical assets. When the number of vulnerabilities is minimized, there are fewer opportunities for attackers to compromise a system, and security professionals can better allocate time and tools to defend high-value targets and respond to threats.

Mapping the Attack Surface: Assets, Entry Points, and Vulnerabilities

Mapping the attack surface involves identifying the organization’s digital assets, potential entry points, and existing vulnerabilities.

Digital assets encompass anything connected to the network that stores or processes data, including:

  • Servers
  • Endpoint devices (e.g. desktops, laptops, mobile devices)
  • Networking equipment (e.g. routers, switches, firewalls)
  • Internet of Things (IoT) devices (e.g. security cameras, HVAC systems)

Entry points refer to any path that could be exploited to gain access to the network, such as:

  • Public-facing web applications
  • Remote access software
  • Wireless networks
  • USB ports

Vulnerabilities are weaknesses in an asset or entry point that could be leveraged in an attack, for instance:

  • Unpatched software
  • Default or weak passwords
  • Improper access controls
  • Lack of encryption

By gaining visibility into all digital assets, entry points, and vulnerabilities across the organization, security teams can work to reduce the overall attack surface and strengthen cyber defenses. This may involve activities such as disabling unnecessary entry points, implementing stronger access controls, deploying software updates, and educating users on security best practices.

Continuously monitoring the attack surface is key to maintaining robust cybersecurity. As new technologies are adopted and networks become more complex, the attack surface will inevitably evolve, creating new security risks that must be identified and mitigated.

Attack Surface Reduction: Eliminating Entry Points and Hardening Assets

Reducing an organization’s attack surface involves eliminating potential entry points and hardening critical assets. This includes removing unused internet-facing services and unused open ports, decommissioning legacy systems, and patching known vulnerabilities across the infrastructure.

Strict access control and least-privilege policies should be implemented to limit adversary access to sensitive data and systems. MFA and single sign-on (SSO) solutions provide additional account protection. Regularly auditing user and group access rights to ensure they are still appropriate and revoking unused credentials minimizes the attack surface.

Firewalls, routers and servers should be hardened through disabling unused functionality, removing default accounts, and enabling logging and monitoring. Keeping software up to date with the latest patches prevents known vulnerabilities from being exploited.

Network segmentation and micro-segmentation compartmentalize the infrastructure into smaller, isolated sections. This way, if an adversary gains access to one segment, lateral movement to other areas is restricted. Zero-trust models should be applied, where no part of the network is implicitly trusted.

Conducting regular risk assessments, vulnerability scans, and penetration tests identifies weaknesses in the infrastructure before they can be exploited. Closing security gaps and remediating high and critical risk findings reduce the overall attack surface.

Maintaining a minimal attack surface requires continuous effort and resources to identify new risks, reassess existing controls, and make improvements. However, the investment in a robust security posture yields substantial benefits, allowing organizations to operate with confidence in today’s threat landscape. Overall, concentrating on eliminating entry points, hardening critical assets, and adopting a zero-trust approach is key to successfully reducing the attack surface.

Identity as an Attack Surface

Identity is an increasingly important attack surface for organizations to manage. As companies adopt cloud services and employees access critical systems remotely, identity and access management becomes crucial to security.

Weak, stolen, or compromised credentials pose a significant gap. Login details of users are often targeted by attackers since gaining control of authorized accounts can grant the attacker access to an organization’s resources.Phishing emails and malware aim to trick users into providing usernames and passwords. Once user credentials have been obtained, attackers can use them to login and access sensitive data, deploy ransomware, or maintain persistence within the network.

MFA adds an extra layer of identity protection. Requiring not just a password but also a code sent to a mobile device or hardware token helps prevent unauthorized access, even if the password is stolen. Adaptive authentication takes this a step further by analyzing user behavior and locations to detect anomalies that could signal account compromise.

Privileged Access Management (PAM) limits what authenticated users can do within systems and applications. Only providing administrators the minimum level of access needed to do their jobs reduces the potential impact of a compromised account. Strictly controlling and monitoring privileged accounts, which have the highest level of access, is especially important.

Managing external access for third parties like contractors or business partners introduces more risks. Ensuring partners follow strong security practices and limiting their access to only what is necessary is key. Terminating all access when relationships end is equally important.

Effective identity and access management involves balancing security and usability. Overly complex controls can frustrate employees and reduce productivity, but weak access policies leave organizations vulnerable. With the right strategy and solutions in place, companies can reduce identity-based risks while enabling business operations.

Continuous Attack Surface Management: A Security Best Practice

Continuous attack surface management is a recommended best practice in cybersecurity. It refers to the ongoing process of discovering, cataloging, and mitigating vulnerabilities across an organization’s entire attack surface – which includes all digital assets, connections and access points that could be targeted.


The first step is discovering and mapping all components of the attack surface, including:

  • Networks, servers, endpoints, mobile devices, IoT devices, web applications, software, etc.
  • All external connections and access points to these assets like WiFi networks, VPNs, third-party integrations, etc.
  • Any vulnerabilities, misconfigurations or weaknesses associated with these components that could be exploited, such as social engineering.


Once the attack surface has been mapped, continuous monitoring is required. As new digital assets, connections and technologies are added, the attack surface changes and expands, creating new vulnerabilities. Continuous monitoring tracks these changes to identify new vulnerabilities and keep the attack surface map up to date.


With visibility into the attack surface and vulnerabilities, security teams can then prioritize and remediate risks. This includes patching software, updating configurations, implementing additional security controls, decommissioning unneeded assets, and restricting access. Remediation efforts must also be continuous to address new vulnerabilities as they emerge.

Continuous attack surface management is an iterative process that allows organizations to shrink their attack surface over time through discovery, monitoring, and remediation. By maintaining a complete and updated understanding of the attack surface, security teams can better defend digital assets and prevent successful breaches.