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Explaining Vulnerability Scanner

A vulnerability scanner is an automated vulnerability testing tool that monitors for misconfigurations or coding flaws that pose cybersecurity threats.

A vulnerability scanner is an automated vulnerability testing tool that monitors for misconfigurations or coding flaws that pose cybersecurity threats. Vulnerability scanners either rely on a database of known vulnerabilities or probe for common flaw types to discover unknown vulnerabilities. The scanner logs detect vulnerabilities and sometimes assign a risk score.

Vulnerability scanners can be categorized by the following operational modalities:

The 3 most common types of scanners

  1. Network vulnerability scanners
  2. Web application vulnerability scanners
  3. Open-source vulnerability scanners


Network vulnerability scanners monitor web servers, their operating systems, their daemons, and any other services open to the internet such as database services.

Network vulnerability scanners work against a database of known vulnerabilities. Many of these databases rely on the Common Vulnerabilities and Exposures (CVE) Program’s free and comprehensive catalog of known software and firmware vulnerabilities. Each standardized record is comprised of a unique CVE identifier, a brief description, and at least one public reference.

Going one step further, the Common Vulnerability Scoring System (CVSS) enriches the CVE List with a numerical score of the vulnerability’s technical severity. However, the best network vulnerability scanning results are achieved with proprietary vulnerability databases that continuously aggregate and analyze information from a wide range of sources.

This heightened ability to extract maximal insights into network vulnerabilities is also important for operational reasons. The not-for-profit Center for Internet Security (CIS) maintains a set of CIS Controls to help organizations implement cybersecurity best practices. One of the basic controls is that vulnerability management — including scanning — be continuous. However, because network vulnerability scans can cause congestion, scans are typically carried out only once a week. It is therefore critical that these scans be carried out against an enriched database that provides comprehensive coverage of known and unknown vulnerabilities.


Web vulnerability scanners scan application/website code to find vulnerabilities that compromise the application/website itself or its back-end services. They are an essential component of application security testing.

These scanners work against a known list of common exploits as maintained by OWASP and others. These exploits use the various injection and evasion techniques to “hijack” web applications and websites to exfiltrate data, trick users or systems into providing sensitive information, or disrupt application performance. Some of the better-known exploits are SQL injection, cross-site scripting (XSS), man-in-the-middle (MITM) attacks, and malicious code.

When it comes to web applications, the only effective vulnerability management strategy is to adopt a shift-left DevSecOps approach and deploy scanners throughout a secure SDLC (software development life cycle). This battery of scanners includes static application security tools (SAST) that automatically scan uncompiled code for vulnerabilities, and dynamic application security tools (DAST) that automatically scan compiled code across all environments from testing to production.

Another important tool is penetration testing, which essentially simulates hackers discovering if a web application or website is vulnerable to malicious exploits. There are even website vulnerability scanner online services that conduct third-party penetration testing.


Open-source vulnerability scanners are software composition analysis (SCA) tools that scan applications to discover all open-source frameworks and libraries — including all direct and indirect dependencies — and identify vulnerabilities. Some open-source vulnerability scanners also help developers in the non-trivial task of precisely locating the vulnerable code in the codebase.

Seeing that using components with known vulnerabilities is one of the OWASP Top 10 vulnerabilities, organizations must ensure that they are using a state-of-the-art open-source vulnerability scanner.

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Arth Kumar


Hi I am Arth, A Python and Wix developer Also Interested in Generative Art(intagram:coder_kumar) If you want a good looking personal website Contact Me
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