Welcome to Attack Surface Management
Over the years, vulnerability management (VM) was performed in conjunction with penetration testing, vulnerability scanning, and web app assessments. These were some of the key players in helping us understand which of our technology assets are susceptible to ransomware threats and identify where the vulnerabilities lie within our organization to quickly seal up. However, with the widespread cloud migration and online presence, the average business’s digital footprint has expanded exponentially.
Today’s attack surface extends beyond your physical IT assets, now encompassing your entire digital footprint. This expansion has fundamentally changed the surface area that security teams must protect. Gone are the days of vulnerability management serving as an adequate defense for your attack surface… today’s cybersecurity professionals have to think bigger: they have to think about attack surface management (ASM).
Vulnerability management is essentially a subset of attack surface management. Vulnerability management simulates the tactics, techniques, and procedures (TTPs) of real-world attackers, which not only gives visibility into the health of a cybersecurity program but also offers clear, actionable solutions to prevent hackers from infiltrating a business’s systems.
By implementing a regular cadence of vulnerability assessments and management testing tools, you are taking a critical step in helping your organization bulk up its cybersecurity posture. But keep in mind, this step is merely a subset of the robust attack surface management program.
With attack surface management (ASM), you’re pursuing the continual identification, inventory, classification, priority, and security monitoring of internal & external digital assets that store, transmit, or process sensitive data.
Your attack surface includes all of your assets that store your data – from hardware to software – that are accessible from the internet. Think of susceptible areas on your “surface” as attack vectors. Any unknown, unprotected, and unmonitored assets can be seen as an opportunity for bad actors. In other words, everything that bad actors can and will learn about vulnerable businesses as they investigate the threat landscape will be included in your ASM planning.
Vulnerability Management vs. Attack Surface Management --
How are they alike/different?
Related Resource: Ransomware Trends in 2021
The best way to manage your attack surface is to shrink your attack surface… but that is easier said than done. There are a few challenges that arise when attempting to shrink an attack surface.
Shadow IT → Your organization’s central IT team cannot protect what they cannot see… and that’s the definition of shadow IT. When remote workers are putting up workstations or servers to meet their immediate needs, meeting corporate security protocols often isn’t a priority. These endpoints go unpatched, unprotected, creating an easy opportunity for an attack.
Mergers and Acquisitions (M&A) → In many mergers and acquisitions, the company being acquired doesn’t have up-to-date records of all its assets. As a result, this creates a similar situation where there could be assets that are not patched or tested, leading to out-of-date and vulnerable operating systems, frameworks, and third-party applications.
While shadow IT and M&As are the primary challenge to effective ASM, there are a few additional contributors to an expanded attack surface:
Bad Actors may have a better understanding of your attack surface than you do. And that’s due to the fact that most organizations don't exactly have a complete picture of their assets. Until a detailed audit is conducted, these assets remain undiscovered, leaving vulnerable spots on your attack surface. In short, all it takes for an attacker to set in motion a cyber attack is simply one vulnerable point in your organization.
Related Reading: 3 Reasons Why You Need a Human-Run Penetration Test
Sun Tzu’s “Art of War” aptly outlines what it takes to have a comprehensive approach to attack surface management:
“If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat.”
In other words, when managing your attack surface, the key to victory is to have both strategy and tactics based on a deep understanding of your company, your team, and your processes, in addition to a solid understanding of the threats you’re up against. With this knowledge, you’ll be able to see the full picture of how to protect your business.
The Avertium team takes this approach to help you stay ahead of any attackers or threats. In this case, a comprehensive approach to ASM – knowing thy self and knowing thy enemy – starts by taking the following steps into consideration:
1. Asset discovery and identification →
Some organizations will utilize Open Source Intelligence (OSINT) and Dark Web enumeration to identify their attack surface – similar to the information that an attacker can see while they plan attacks against your organization. By doing this, businesses will have an idea of how an attack might be conceived and start brainstorming the measures they need to take to mitigate it.
It’s good to note that this can also assess your physical and software assets, identifying what functions and parts of the system you will need to review/test for security vulnerabilities.
When going through this step, some good questions to ask are:
2. Classification and prioritization →
Once your assets have been thoroughly discovered, you can categorize and prioritize them according to each one’s level of risk – from assets that need to be remediated immediately to assets that can wait according to your specific risk appetite. It’s important to identify the high-risk areas first and work backward.
It’s important to take into account any and all remote entry points – interfaces with outside systems and to the Internet – and especially, areas where the system allows anonymous, public access. Oftentimes, these are where you are most exposed to an attack.
3. Security ratings and risk scoring →
Effective attack surface management is only possible once relevant assets and potential vulnerabilities are identified and categorized by rating and scoring. Discovery must include a comprehensive network scan and system audit. Sophisticated software tools and applications can effectively automate a large part of this process.
The catalog of assets should be classified according to potential vulnerabilities, as well as configuration, patch, and compliance states, which generates an initial risk assessment.
Risk is then reduced by applying controls reducing the threat posed by the vulnerability. In a cybersecurity context, this can include operations like segregating vulnerable portions of the network or devices or deploying enhanced authentication or authorization solutions. Generally, this is accomplished accordingly by the rating and scoring of the identified asset.
4. Continuous security monitoring →
Continuous network monitoring is required to stay abreast of today's sophisticated attacks. This means the catalog of assets must also be continually refreshed to stay up-to-date, but this also means leveraging the right tools and technologies to continuously monitor your attack surface.
Extended Detection and Response (XDR) integrates advanced technologies and applications designed to surpass the limitations of current solutions. It integrates enhanced visibility (24/7/365) across your networks, clouds, applications, and endpoints with automated detection and response tools that react quickly to thwart both existing and emergent threats.
By spotlighting the most critical threats for your security team to focus on, XDR enables organizations to get the broadest, most contextually relevant view of their entire attack surface.
5. Security threat intelligence →
Knowing thy enemy starts with gathering intelligence on potential adversaries' tactics, techniques, and procedures (TTPs). You can also work with a trusted partner such as Avertium to leverage our Cyber Threat Intelligence (CTI) Resources to further strengthen your security processes.
Note: Michael Howard at Microsoft and other researchers have developed a method for measuring the attack surface of an application, and to track changes to the attack surface over time, called the Relative Attack Surface Quotient (RSQ). Using this method you calculate an overall attack surface score for the system and measure this score as changes are made to the system and to how it is deployed. Researchers at Carnegie Mellon built on this work to develop a formal way to calculate an Attack Surface Metric for large systems like SAP. They calculate the attack surface as the sum of all entry and exit points, channels (the different ways that clients or external systems connect to the system, including TCP/UDP ports, RPC endpoints, named pipes...), and untrusted data elements. Then they apply a damage potential/effort ratio to these attack surface elements to identify high-risk areas.
Related Reading: 8 Essential Steps to Take After a Data Breach
Expanding endpoints, cloud computing environments, accelerated digital transformation, and the move to work from home have decimated the perimeter. Avertium's approach to attack surface management empowers companies with the strategic insight needed to drive board-level decisions, blending tactical action with a big-picture approach that protects business-critical assets.