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Attack Surface Analysis Guide

by John Cirelly - Last Updated: March 17, 2022

Attack Surface Analysis Guide

In this article, you’ll learn how to do Attack Surface Analysis and manage an application’s Attack Surface. Application security professionals and developers alike may use it to better understand and manage the security risks associated with developing and modifying an app.

Outsider assaults are not included in the scope of this article, but the ideas are still applicable to defending an application against inside threats (such as social engineering attacks or malicious software). The exterior attack surface is likely to be different from the internal attack surface, and certain users may have a great deal of access to the network and its resources.

What is Attack Surface Analysis?

Attack Surface Analysis is the process of determining which sections of a system need to be examined for security flaws. When it comes to an application’s attack surface, the goal is to identify risk areas, make developers aware of these areas, and create solutions to reduce the danger of an attack, as well as keep track of the Attack Surface’s evolution.

Security architects and pen testers are often the ones that do attack surface analysis. However, while designing, developing, and modifying a system, developers should be aware of the Attack Surface and keep an eye on it.

Using Attack Surface Analysis, you may do the following:

  • The first step is to figure out what functions and what portions of the system need to be reviewed/tested for security vulnerabilities.
  •  Identify and protect high-risk parts of code.
  • How much security do you need for each aspect of the system? Determine when you need to conduct a threat assessment due to a change in the attack surface.

What is an Attack Surface?

The Attack Surface is a list of all of the places where an attacker may get access to a system, as well as all of the places where they could remove data from the system.

  1. Data and command pathways into and out of an application are counted as part of an application’s attack surface.
  2. The code that safeguards these routes (including resource connection and authentication, authorization, activity logging, data validation, and encoding)
  3. Secrets and keys, intellectual property, vital corporate data, personal data, and PII as well as every other valuable information utilized in the program must be encrypted.
  4. Code that safeguards the data (including encryption and checksums, access auditing, data integrity, and operational security controls).

Users of various roles and permission levels may access the system by overlaying this model on top (whether authorized or not). The greater the number of users, the greater the complexity. The focus should be on the two extremes: unauthenticated, anonymous users and highly powerful administrators (e.g. database administrators, system administrators).

Each sort of attack point should be classified according to its risk (external or internal), goal, implementation, design, and technology. Then you may tally the number of attack points for each category, choose a few examples for each type, and concentrate your review/assessment on them.

The Attack Surface and the possible risk profile of a system do not need an in-depth knowledge of every endpoint using this technique. As an alternative, you may instead count the various types and the number of points in each kind. The cost of risk assessment at scale may be budgeted, and the change in an application’s risk profile can be detected.

Strategies for analyzing the attack surface

The attack surface is referred to in a variety of ways. A “digital attack surface” or “digital footprint” is another term for it. An alternative phrase for “outside assault surface” is “inside attack surface”. Internal and external attack surface analysis methodologies are shown in this diagram, which is similar to the approaches used for vulnerability scanning.

The external method to attack surface analysis examines how a hacker sitting in a remote location might get access to your data storage via your software. This method examines how a user account may obtain ahold of your information.

Detection of insider threats and hijacked accounts is the primary goal of Internal Attack Surface Analysis (IAST). Disgruntled employees or employees deceived into taking action by phishing might be the source of an insider threat. Phishing, on the other hand, may get a hacker access to an authorized user’s login credentials.

Data leakage may occur when other systems, such as APIs or managed services, handle your company’s data. This is where external attack surface analysis comes in. Access rights management is the topic of internal attack surface analysis.

Identifying and analyzing an attack surface

Analysis of a system’s attack surface is primarily concerned with identifying weak points and increasing the possibility of an attack. One of the easiest ways to accomplish this goal is to minimize the surface of your defenses that may be attacked.

User account management should be the primary focus of an internal attack surface study. Look at the user groups you’ve created in your identity and access management system to see if you can better define each of these groups. After that, you’ll need to figure out which user accounts belong to each group.

Automated procedures have a hard time keeping track of backend accounts. There’s nothing you can do about this, and it increases your attack surface. These secondary data accessing programs would not be able to function efficiently if they were restricted. If you have a solid purpose for purchasing and installing these programs, you must allow them to work.

Secondary access may be prevented by implementing strict access restrictions on all packages. Let’s pretend that these software products aren’t used by users at all, but instead transfer data to a third party through automatic means. If that is the case, you have a new assault surface to contend with. External attack surface analysis might potentially be a part of this.

Implementation attack surface analysis

Expertise in the field of attack surface analysis is required. In the past, penetration testers were the ones to do it. In other words, a “pen tester” simulates the actions of a hacker by attempting to get access to a system by whatever means necessary. Because they don’t want to disrupt the system or compromise their security to the fullest, system administrators and corporate insiders often don’t go to the extremes that a hacker would.

Start with an eDiscovery procedure to identify and classify each data storage. This means that each place will have a separate sensitivity classification. Track all of the access points to the highest-rated data initially. The software that accesses that data must be linked to the software that interacts with that initial circle of software. Continue the back-chaining process until no more data is being shared.

This procedure must be repeated for every category of data in every data storage. Mark the border between internal and external systems in every data flow.

Measuring and Assessing the Attack surface

Determine which areas of the Attack Surface are most vulnerable. Make use of systems that allow anonymous, public access at remote entry points, such as those connecting to external systems or the Internet.

Backward compatible interfaces with other systems – old protocols, sometimes old code and libraries, difficult to maintain and test multiple versions of multiple systems Code involving encryption, authentication, permission (access control), or session management is particularly vulnerable to errors in design and implementation since it is written specifically for a certain application. At these points, you are most vulnerable to harm. Finally, take a look at operational controls, such as network security controls and application security controls, to ensure that your application is safe.

Managing the attack surface analysis

Having a baseline awareness of the Attack Surface allows you to detect and manage risks when you make modifications to the application. Ask yourself:

  • Has anything changed?
  • What’s distinctive about you? (Technology, a fresh approach).
  • Is there a way I could have done more?

When you establish your first webpage, you greatly increase the Attack Surface of your system and add a host of new dangers. While adding a new field to that page, or a similar web page, technically increases the Attack Surface, it does not affect the application’s risk profile. It’s more of the same with each iteration, barring a radical shift in approach or architecture.

Performing the same sort of risk assessment and analysis whenever you introduce new user types, roles, and permission levels is a good practice. Investigate any issues or discrepancies by comparing the different types of access to the data and services. It is critical to know the application’s access model, whether it is positive (access is granted by default) or negative (access is denied).

Any flaws in describing what data or functions are authorized to a new user type or role are obvious in a positive access model. If you employ a negative access model, you must be significantly more watchful to make sure that a user does not get access to data or services that they are not supposed to.

When it comes to assessing threats and risks, this may be done regularly, as part of the design process in serial, phased and spiral projects, or it can be done constantly and incrementally in Agile projects.


The Attack Surface of an application often grows as new user types and interfaces are added, as well as when the system is integrated with other systems. To further minimize the Attack Surface, you should look for ways to reduce complexity (such as reducing the number of user levels or not storing confidential data) and turn off features and interfaces that aren’t being used, as well as implementing operational controls such as a Web Application Firewall (WAF) and real-time application attack detection.