Beyond the Perimeter: Exploring the Modern Attack Surface

Attack surface analysis is critical in securing your infrastructure and providing insight into potential ways intruders can exploit application and network vulnerabilities. Performing attack surface analysis positions you to prioritize risks and prepare mitigation strategies. A comprehensive attack surface analysis supports a proactive Offensive Security Strategy by identifying the vulnerabilities bad actors will seek to exploit.

In this blog, we'll provide an overview of attack surface analysis. We'll cover:

• What attack surface analysis is and what it's for?
• Real-world attack surface examples
• What Is Attack Surface Analysis? 

Attack Surface Analysis Defined

Attack surface analysis is a continuous, comprehensive assessment of all the ways intruders can access your network, known as attack vectors. Attack vectors include all vulnerabilities, pathways of access, and methods of exploitation. Analysis of these vectors covers all digital risks, social engineering risks, and physical risks such as malicious insiders.

An attack surface analysis investigates all paths for data and commands into and out of applications, all data used by applications, all code protecting these paths and data, and all types of users. A security analyst then groups threats based on criteria such as purpose, design, implementation, and technology.

In contrast to other cybersecurity strategies, attack surface analysis identifies and catalogs vulnerabilities in your system. It can uncover vulnerabilities that may be overlooked when analyzing your system from the defender's perspective.

Purpose of Attack Surface Analysis

Attack surface analysis forms a critical step in attack surface management (ASM). ASM seeks to identify, analyze, and mitigate potential exploits hackers might use. To prepare for attack surface analysis, ASM inventories and monitors all Internet-facing digital assets, including on-premise and cloud assets.

This sets the stage for analysis and prioritization of attack surface vulnerabilities. 

The analysis is followed up by short-term and long-term steps to reduce and remediate vulnerabilities. Short-term attack reduction actions may include steps such as adjusting security controls, applying patches, and deactivating unnecessary apps. 

Long-term mitigations should involve a comprehensive reassessment and enhancement of the security program, encompassing aspects like vulnerability management, security awareness training, incident response planning, and the continuous monitoring and improvement of security controls.

Real-world Attack Surface Analysis Examples

Security teams can apply attack surface analysis to any on-premise or cloud-based vulnerability, access pathway, or exploitation method, uncovering risks ranging from exposed credentials, and generic tokens to missing security headers and takeover risks. To illustrate what an attack surface analysis looks like, here are three real-life examples representing some common scenarios.

Directory Listing Sensitive Information Disclosure Vulnerability

This example focuses on a content management system with an upload directory configured to display its contents—directories and files—due to enabled directory listing. Now say that employees have uploaded unencrypted files containing personally identifiable information, such as human resource files. If an attacker discovers the directory, they can steal the information.

Attackers typically discover directory listing vulnerabilities by stumbling across them through search engines, constructing queries to exploit common directory naming conventions, mining cached data, or running automated tools such as network scanners. Attack surface analysts can use similar methods to uncover directory listing vulnerabilities.

Archive File Backup File Disclosure Vulnerability

In this illustration, consider the case of an archive file stored in an application host's root-level domain with the name of the domain in the file prefix. The archive file contains a backup of the application, source code, user data, and hashed passwords. 

In addition to stealing the source code, an attacker who discovered the file potentially could use password cracking to extract plaintext passwords from the hashed passwords. By identifying valid passwords, the attacker then could log into the application, take over user accounts, and begin stealing information or distributing malware. Furthermore, the attacker potentially could take over the application's infrastructure, run adversary-in-the-middle attacks, launch ransomware attacks, or conduct other attacks.

This vulnerability typically stems from poor selection of backup file locations, insecure access configurations, and weak access control and authentication procedures. To analyze this attack surface, backup files can be identified and located by scanning for files with common extensions.

Misconfiguration Subdomain Takeover Vulnerability

In this scenario, consider the case of a DNS subdomain record that has been misconfigured to direct traffic to a third-party website, such as an expired domain previously used by the domain owner. An attacker notices the expired domain is available, registers ownership of it, and uses it to run attacks on visitors or seize control of the victim's domain. Attackers can potentially read cookies from the victim's domain, run cross-site scripting exploits, and bypass content security policies. If the subdomain is trusted by other sites, attackers who log into it can even exploit their credentials to bypass Single Sign-On authentication on other services.

This vulnerability typically occurs when subdomains have canonical names in DNS records without a host providing content. Attack surface analysts can uncover it by enumerating DNS servers using methods such as using a list of common subdomain dictionaries, DNS brute forcing, or conducting search engine reconnaissance. After DNS servers have been enumerated, DNS resource records pointing to inactive domains can be identified.

Analyze Your Attack Surface with Cobalt Attack Surface Solutions

Attack surface analysis forms a foundation for effective cybersecurity, providing teams with a list of endpoints and potential vulnerabilities in your system. It's the starting place for an outside-in offensive security approach and an effective start to scope a pentest, similar to the way a hacker would try to break into your systems. Armed with this information, you can prepare effective mitigation strategies and conduct better informed penetration tests.

The Cobalt Platform includes attack surface discovery and monitoring features to help you uncover potential vulnerabilities. With the Attack Surface Management feature to help you understand what Targets under your Domains are externally reachable, ensuring that all assets in their environment can be properly secured.

Our attack surface discovery tools represent just one component of our cutting-edge offensive security testing platform. Our platform encompasses attack surface monitoring, automated scanning with DAST, pentesting, and offensive security engagements. 

Through our platform, your security team can collaborate with our network of experienced pentesters, led by a core of professionals to maintain up-to-date cybersecurity best practices. Contact us to discuss how we can help you secure your attack surface.