Attack Surface Management (ASM) is a cybersecurity strategy designed to identify, monitor, and manage all potential entry points where an organization might be vulnerable to cyberattacks. These entry points, collectively called the attack surface, include both internal and external assets such as cloud services, IoT devices, software applications, APIs, systems managed by third-party vendors, and shadow IT resources operating outside traditional oversight.
As organizations adopt hybrid work models, cloud computing, and other digital transformation initiatives, their attack surface grows increasingly complex. ASM cybersecurity addresses this complexity by viewing the attack surface from an "outside-in" perspective, mimicking an attacker's approach to uncover hidden vulnerabilities.
ASM security comprises four fundamental components:
Unlike traditional asset management, which often relies on static inventories, ASM adapts in real-time, leveraging automation to keep pace with the threat landscape.
The external attack surface consists of online resources like websites, public APIs, and cloud services. Since these are the main ways attackers can get in, managing the external attack surface is crucial. With organizations increasingly leveraging cloud solutions and remote work, this category continues to expand, exposing assets like unpatched systems and misconfigured cloud infrastructure to significant risks. The external attack surface evolves with every SaaS deployment, new API, or forgotten cloud resource.
Internal attack surfaces encompass systems within an organization's network perimeter, such as employee devices, databases, and internal applications. While shielded from direct external threats, these assets are vulnerable to insider risks, misconfigurations, and lateral movement by attackers who breach external defenses. The internal attack surface also includes risks originating from human factors, such as insider threats or inadvertent misconfigurations, underscoring the importance of both technical and organizational security controls.
Known attack surfaces are documented assets actively managed by security teams through regular assessments and monitoring. In contrast, unknown attack surfaces - often referred to as shadow IT - include unauthorized devices, forgotten systems, and rogue IoT devices. Unknown attack surfaces create blind spots that increase the risk of exploitation and weaken the organization's security posture. These often appear during events like mergers and acquisitions, where new systems or undocumented resources bring unexpected vulnerabilities.
The physical attack surface includes physical items like hardware, data centers, and network equipment. Threats here include stealing devices, tampering with equipment, and unauthorized physical access. While physical vulnerabilities may seem disconnected from digital threats, attackers often exploit physical breaches to gain access to internal or digital assets, highlighting the interconnected nature of attack surfaces.
Spanning software, hardware, and internet-connected resources, the digital attack surface includes applications, APIs, and cloud-based platforms. Subcategories like the cloud attack surface and network attack surface add layers of complexity, as organizations must secure assets across diverse platforms and rapidly evolving technologies.
Organizations are under constant attack from cyber attackers who use many different methods—called "attack vectors"—to get into systems. To defend effectively, organizations need to take an "outside-in" approach, to see their systems as an attacker would, to find weaknesses before they get exploited.
Attack vectors are the paths attackers use to get into systems, and they evolve with the technologies organizations adopt. Here are a few examples:
1. Phishing Attacks: Deceptive emails and websites manipulate individuals into divulging sensitive information, such as passwords. Attackers recognize that humans constitute the weakest link and employ social engineering techniques to exploit trust and emotion.
2. Exploiting Vulnerabilities: Outdated software or misconfigured systems create security gaps, such as the widely publicized Log4j bug. Attackers target these flaws, often before organizations can fix them.
3. Ransomware: Attackers use malware lock critical data or systems and demand payment to unlock them, disrupting operations and pressuring businesses to pay to resume normal activities.
4. Supply Chain and Third-Party Risks: Partners or suppliers with weaker security are often targeted as an entry point into larger organizations.
5. Rogue and Shadow IT Assets: Employees use unapproved devices or apps, creating "blind spots" in security.
Different threat actors have different motivations and skill levels:
As organizations grow - adding cloud services, supporting remote work, and merging with other companies - their systems become more complex and harder to track. This leads to "attack surface drift," where gaps and unmonitored systems emerge. Understanding these attack vectors and the actors who exploit them is crucial for developing effective ASM strategies that protect against evolving threats.
Asset Discovery
Asset discovery is the first step in ASM, which involves finding all public-facing digital assets. These include websites, APIs, IoT devices, cloud services, shadow IT (unauthorized tools or systems), and vendor connections. You can find unknown assets, determine their role, and monitor them throughout their lifecycle—from deployment to decommissioning. This foundational step ensures no vulnerabilities are left unaccounted for.
Inventory and Classification
After finding all the assets, the next step is to list and sort them. Each asset is grouped by its type, purpose, value, owner, and rules it must follow. This sorting helps security teams focus on the most important or risky assets. By labeling each asset and its role, you can better handle the risks from unauthorized systems or old tools.
Vulnerability Analysis
Once assets are cataloged, they go through vulnerability analysis to find weaknesses such as outdated software, misconfigurations, or insecure APIs. ASM combines automated scans with expert-driven methods like red-teaming to simulate how attackers would exploit these weaknesses. This dual approach gives you comprehensive insights so you can develop a plan to address the risks found.
Risk Prioritization
Not all vulnerabilities are equal. ASM scores each weakness based on the likelihood of exploitation, business impact, and remediation complexity. This allows security teams to tackle the most critical risks first. As new threats emerge and assets change, priorities are adjusted dynamically so the organization stays focused on the most pressing issues.
Continuous Monitoring and Metrics
Technology changes daily, so it's important to keep checking the attack surface all the time. ASM watches over assets for new problems, mistakes in setup, and any changes. This also includes looking out for risks from outside vendors or suppliers, which the organization can't always control. ASM also tracks performance metrics, such as mean time to inventory (MTTI), to measure how quickly assets are discovered and risks are mitigated. These metrics help organizations refine their security strategies and demonstrate progress.
Attack Surface Management (ASM) gives organizations a clear understanding of every digital entry point that attackers might exploit. As businesses expand their operations through cloud computing, hybrid work environments, and connected devices, their attack surface grows. This expansion, combined with the increasing sophistication of cyber threats, makes comprehensive visibility and control critical for security.
ASM uses advanced automation to monitor assets, detect emerging vulnerabilities, and address them faster than manual methods ever could. This ability is very important because today's attacks can spread quickly through connected systems, and company networks are becoming more complicated. Without good Attack Surface Management (ASM), organizations might not find important security weaknesses until it's too late.
ASM offers several key advantages that enhance an organization's security posture.
ASM provides continuous visibility across an organization's digital footprint, including shadow IT, rogue assets, and cloud services. By adopting an outside-in perspective - like that of a potential attacker - ASM identifies risks that traditional methods often miss. This is particularly useful during times of change, like mergers or rapid expansion, when visibility can disappear.
Through data-driven analysis, ASM lets you prioritize risks based on how likely they are to be exploited and their business impact. No more treating all vulnerabilities equally and focusing on the threats that can do the most harm. This means better security outcomes and better decision-making.
With automation, ASM simplifies workflows and reduces manual work. Security teams can focus on strategic initiatives, not repetitive tasks. Security teams can spend their time on strategic initiatives rather than repetitive tasks. This is key for overworked teams to focus on critical vulnerabilities while identifying and eliminating duplication.
When incidents happen, ASM speeds up response with detailed asset lists and real-time risk visibility. By moving at the speed of modern threats, ASM detects and mitigates vulnerabilities—often before they can be exploited. This reduces the damage and recovery time and increases overall resilience.
Attack Surface Management (ASM) and Vulnerability Management (VM) are essential but distinct parts of cybersecurity strategy. Vulnerability Management is about finding and remediating known weaknesses in the organization's systems and software. It operates within the boundaries of the organization's asset list, using scans and patches to secure known assets. ASM takes a broader approach, examining the organization from an attacker's perspective to continuously discover and monitor all potential entry points - including those previously unknown. These can include shadow IT, such as unauthorized cloud services, unapproved devices, or systems that never made it onto official inventories.
Exposure Management (EM) helps prioritize risks by understanding vulnerabilities within an organization's threat environment. Both ASM and Exposure Management look for risks before they become problems, but ASM stands out because it finds hidden assets and how attackers might access them. This improvement helps Exposure Management by giving important information and allowing better use of resources.
For Chief Information Security Officers (CISOs), ASM means moving from traditional inside-out methods to an outside-in approach that imitates how attackers think. Attackers often scan the entire internet within minutes of a CVE disclosure, targeting untracked or misconfigured assets first. ASM counters this by providing real-time visibility into the attack surface, enabling CISOs to align security investments with business objectives and meet regulatory requirements by accounting for all assets.
External Attack Surface Management (EASM) functions as a specialized component of ASM, focusing specifically on internet-facing assets such as public APIs, websites, and cloud services. While ASM looks at both inside and outside parts, EASM deals only with the risks of things that are available online.
When you combine ASM with Vulnerability Management (VM) and Exposure Management (EM), you create a complete security system. In this system, ASM shows all the ways someone could enter, VM fixes specific problems, and EM makes sure that reducing risks fits the company's goals.
Here's how to put ASM into action effectively:
1. Adopt an Outside-In Approach
Hackers look for overlooked assets or weak spots in your defenses. By viewing your systems the way an attacker would, you can find and secure these vulnerabilities. Why It Matters: Attackers don't follow rules - they search for the easiest way in. Identifying and fixing these weaknesses first makes it much harder for them to succeed.
How to Do It:
2. Focus on the Most Dangerous Problems First
Not all weaknesses are equally risky. By choosing to fix the vulnerabilities that are the biggest threats, you can solve the most urgent problems quickly.
Why It Matters: Fixing the most dangerous problems first keeps important systems and data safe while saving time and resources.
How to Do It:
3. Connect ASM to Compliance and Quick Responses
Many regulations, like GDPR or HIPAA, require organizations to keep sensitive data safe. ASM helps you follow these laws and respond quickly to problems.
Why It Matters: Following the rules avoids fines and keeps customers trusting you. Finding threats early stops serious damage.
How to Do It:
4. Combine Automation with Human Expertise
Automated tools can quickly check and find common weaknesses, but skilled people are needed to solve tough problems and plan long-term fixes.
Why It Matters: Automation is great for scale, but human analysts can spot subtle threats and adapt strategies as attackers evolve.
How to Do It:
5. Keep Adapting to New Threats
The digital landscape is always changing, and attackers constantly invent new tricks. Your ASM approach needs to evolve to keep up.
Why It Matters: Updating your defenses ensures you're ready for new vulnerabilities and that older protections remain effective.
How to Do It:
6. Get Ahead of Attackers by Being Proactive
Don't wait for a breach to happen - find and fix potential issues before they become problems.
Why It Matters: Preventing attacks is cheaper, faster, and safer than dealing with the aftermath of a breach.
How to Do It:
ASM tools automate the discovery and monitoring of digital assets so that organizations can have visibility and control over their security landscape.
Modern ASM tools have these key features to keep you secure:
Choosing the right ASM tool is about balancing technical capabilities with your organization's needs. Consider:
Bitdefender's GravityZone platform offers a comprehensive approach to Attack Surface Management (ASM), delivering visibility and control over your entire attack surface. We help you proactively identify and mitigate risks using advanced technologies. Here's how our key products contribute to a robust ASM strategy. GravityZone Unified Platform is the foundation for your security. It provides centralized management and visibility across your entire infrastructure, including endpoints, servers, cloud environments, and networks.
A crucial component of ASM, External Attack Surface Management (EASM) within GravityZone focuses on identifying and monitoring your internet-facing assets, such as websites, public cloud instances, and APIs. This helps you understand your external vulnerabilities and reduce the risk of external breaches.
Risk Management is a module that helps organizations identify and prioritize risks associated with misconfigurations, vulnerabilities, and user behaviors. It provides a risk assessment score to help admins focus on the most critical areas.
Endpoint Detection and Response (EDR) provides detailed visibility into endpoint activity, allowing you to quickly detect and respond to threats that bypass initial security layers. EDR uses behavioral analysis and machine learning to identify unusual activities. By integrating data from multiple sources like endpoints, networks, cloud, and applications, Extended Detection and Response (XDR) offers a comprehensive view of complex attacks, tracing them from initial breach through lateral movements. Our native XDR approach ensures seamless integration and provides a unified language across all technologies.
For organizations that need 24/7 security, our Managed Detection and Response (MDR) service provides a team of expert security analysts to monitor your environment, hunt for threats, and manage incidents. MDR is powered by the GravityZone platform, and it is available in different tiers depending on the required service.
Patch Management add-on automates the detection and deployment of software patches to address vulnerabilities in your operating systems and applications, thereby reducing the attack surface. It allows you to select which patches to deploy, and also helps you to ignore problematic patches.
Cloud Security Posture Management (CSPM+) provides visibility and security for your cloud environments. It integrates with Amazon Web Services (AWS), Google Cloud Platform (GCP), Microsoft Azure, and Alibaba Cloud to ensure compliance and secure cloud configurations. CSPM+ uses an agentless approach to scan your cloud environment.
Procuring the services of Bitdefender Offensive Security Services, can help expose vulnerabilities in a safe environment. Consisting of penetration testing and red-team exercises, Bitdefender Offensive Security Services can proactively help your business become resilient to attacks by exposing the weak points in your security chain and providing effective remediations.
Attack Surface Management (ASM) and Breach and Attack Simulation (BAS) are two different things in cybersecurity. ASM is a proactive approach that identifies, monitors, and manages all entry points into an organization's systems. It provides visibility across the attack surface, including known and unknown assets.
BAS simulates real-world attacks to test an organization's defenses. It evaluates how existing security tools and configurations respond to the tactics used by threat actors. While ASM identifies vulnerabilities and risk areas, BAS tests how prepared the organization is to respond to threats. Together, they complement each other: ASM highlights what needs securing, and BAS tests whether those defenses are effective
Dynamic Application Security Testing (DAST) and Attack Surface Management (ASM) serve different but complementary security functions. DAST is focused on testing web applications and services by simulating attacks while the application is running, specifically looking for vulnerabilities that become apparent during execution. It operates from the outside, testing specific applications.
ASM takes a broader approach, continuously discovering and monitoring all digital assets across an organization's entire infrastructure, not just web applications. While DAST provides deep testing of specific applications, ASM gives you comprehensive visibility of your entire attack surface, including unknown assets, third-party connections, and shadow IT.
An attack surface represents all possible points where an attacker could attempt to enter or extract data from a system. Think of it as a comprehensive map of every door and window in your house. In contrast, an attack tree is a structured diagram that shows the different paths an attacker might take to achieve a specific goal, like a flowchart showing all the possible ways someone could break into your house - from picking a lock to breaking a window.
Attack trees help analyze specific threats by breaking down complex attack scenarios into smaller, manageable steps. They start with an attacker's ultimate goal at the top (like "gain admin access") and branch down into the various methods and sub-steps that could achieve that goal. While attack surface management focuses on discovering and monitoring all potential entry points, attack trees help security teams understand and analyze specific attack scenarios in detail.