Vulnerability Scanning: Types, Tools, and Importance

What is vulnerability scanning?

Vulnerability scanning is the practice of automatically identifying security flaws within applications and infrastructure.

In most cases, the main purpose of vulnerability scanning is to detect application components or dependencies that are known to pose a risk – which is important because unpatched vulnerabilities account for 60 percent of breaches. However, in a broader sense, vulnerability scanning can also be used to detect configuration risks – which aren’t software vulnerabilities, per se, but which threat actors could still potentially exploit.

Vulnerabilities are only one of the many types of risks that could lead to cybersecurity attacks (others include issues such as malicious insider threats and phishing). For this reason, vulnerability scanning alone isn’t sufficient to detect all potential threats to an organization’s IT resources. But it is one key element of modern cybersecurity because vulnerabilities are one of the most common weaknesses that attackers exploit to compromise applications or the environments that host them.

How does vulnerability scanning work?

Vulnerability scanning works by using tools that can automatically parse an application and detect vulnerable code or dependencies associated with it. Typically, the vulnerability scanning process boils down to the following core steps:

1. IT admins or security analysts determine which software they want to scan for vulnerabilities.
2. Teams deploy a vulnerability scanning tool and point it at the applications.
3. The tool systematically scans the applications for signs of known vulnerabilities by comparing the application’s contents to a vulnerability database (like Aqua’s vulnerability database).
4. The tool generates a report listing the vulnerabilities it discovered. In some cases, the report includes details about how the vulnerabilities can be exploited and how severe they are.

By following these steps for each application they deploy – and by repeating them whenever they update or redeploy an app – organizations can detect many types of security flaws before they release vulnerable code into production. By extension, they can mitigate the risks before attackers are able to exploit them.

Types of vulnerability scanning

Vulnerability scanners can be broken into several categories based on the types of resources they scan and the techniques they use. Key examples include:

• Application scanning: Checks for insecure code or components within applications.
• Network-based scanners: Focus on risky network configurations or untrusted devices.
• Host-based scanning: Comprehensively scans all applications and configurations on a server or other host.
• Database scanning: Can discover sensitive information within databases. This is not a type of vulnerability scanning in the traditional sense of the term because sensitive data doesn’t enable cyberattacks in the way that software vulnerabilities do, but database scanning may still be useful for discovering vulnerable data assets that an organization would otherwise overlook.
• Cloud-based scanning: Scans cloud environments, typically with a focus on detecting insecure cloud configurations.

Note that many of these categories overlap to a certain extent. For example, application scanning could be considered one component of host-based scanning, since most host-based scanners can check for out-of-date or unpatched applications installed on a host. So, rather than thinking of each of the categories described above as a unique type of scanning, think of them as different, interrelated aspects of modern vulnerability scanning.

Pen testing vs. vulnerability scanning

Vulnerability scanning is often compared to penetration testing (or pen testing), a practice that involves manually exploring IT environments and resources for potential security. However, while these processes are similar in some respects, they are not the same.

Key differences between pen testing and vulnerability scanning include:

• Method: Vulnerability scanning is automated, whereas pen testing is usually manual (although pen testers may make use of tools that automate some aspects of the process, such as scanning networks or applications for vulnerabilities that they could exploit).
• Frequency: Because pen tests are mostly manual, it’s only feasible to perform them on a periodic basis. In contrast, vulnerability scanning can be fully automated and performed continuously.
• Depth: Pen testing usually entails attempts to exploit vulnerabilities, which offers more depth into the paths attackers might use to take advantage of them. Vulnerability scanning, by contrast, focuses only on detecting vulnerabilities.
• Cost: Pen testing is usually costly because it requires an extensive time commitment by skilled staff. Vulnerability scanning is more cost-effective because it can be automated using tools.
• Skill level requirement: Pen testing necessitates specialized cybersecurity skills. Vulnerability testing also requires some familiarity with cybersecurity concepts, but often not at the same level. This makes it feasible for IT teams who are not security experts to perform vulnerability scanning, whereas only cybersecurity professionals can carry out effective pen tests.
• Scope: Pen tests usually focus on specific systems or resources, whereas vulnerability scanners can comprehensively scan all assets within an organization’s IT estate.

The following table summarizes the key differences between each type of security testing.

How to choose vulnerability scanning tools

All vulnerability scanning tools offer the same basic feature: The ability to detect vulnerable code or configurations. But some provide additional functionality. To ensure you’re getting the most effective vulnerability scanning tool, consider factors like the following when evaluating solutions:

• Accuracy: How often does the tool report vulnerabilities that don’t actually exist (in other words, false positives) or miss ones that do (meaning false negatives)?
• Coverage: How many types of resources can the tool scan? Does it only work with certain cloud platforms or certain types of applications, for example?
• Integration: How well does the tool integrate with other software development tools to enable continuous, automated scanning as part of the secure software development lifecycle (SSDLC)?
• Compliance: Does the tool align with compliance mandates your organization needs to meet?
• Usability: How easy is the tool to deploy and use? Do you need specialized skills or a complex hosting environment, or can any IT professional run it in a generic environment?
• Reporting: How robust are the tool’s reporting features? Does it only list vulnerabilities, or does it also detail vulnerability exploitability and severity?
• Cost: How much does the tool cost? Think in terms not just of the direct licensing cost, but also the staff cost associated with using the tool, as well as hosting costs if you deploy the tool on your own infrastructure.
• Closed vs. open source: Is the tool fully or partly open source? This is particularly important if you want to be able to customize the tool or create your own integrations for it.

Managing vulnerabilities with Aqua

As a pioneering cloud-security platform, Aqua provides advanced vulnerability scanning tools and features as one of the many features organizations can use to help secure modern workloads. You can deploy our open source Trivy scanner on its own, or take advantage of the vulnerability scanning, assessment and management features that are built into the Aqua platform.
To learn more, request a demo.