Fingerprinting Web Applications and APIs using Qualys Web Application Scanning

Gaurav Phatak

Last updated on: November 3, 2022

Decoding the impact of Fingerprinting

Organizations develop an effective, actionable go-to-market plan to launch a profitable product into the target market. A go-to-market strategy predicts market demand by analyzing market research, competitor data, and previous examples. Without a solid go-to-market plan, you would not know if you have targeted the right audience, if there is market demand or saturation for your solution, or whether you are too early or late in a given market.

Nowadays, almost everything you can imagine has already been developed. Therefore, development teams often use readily available frameworks and libraries to speed up the release process. In the modern web world, most applications directly or indirectly depend on underlying components such as application frameworks, content management systems, databases, libraries, proxies, web servers, and operating systems that might be highly vulnerable.

Here’s where fingerprinting comes into play. Identifying these underlying components can significantly enhance an attacker’s ability to footprint the application and its environment. An attacker discovers and collects information about the system covertly. In cybersecurity, this is known as reconnaissance. This technique analyzes headers, cookies, HTML elements, scripts, metadata, directory structures, and other readily accessible data to fingerprint technologies in application request/response pairs. If attackers discover critical application infrastructure information, they have found a gold mine.

Qualys Web Application Scanner (WAS) Approach

Qualys Web Application Scanning (WAS) is a cloud-based service that provides automated crawling and testing of custom web applications and APIs to identify vulnerabilities, including cross-site scripting (XSS), SQL injection, and many more. This automated service enables regular testing that produces consistent results, reduces false positives, and easily scales to cover thousands of websites. 

With the recent enhancement of our WAS service, we added an advanced proprietary reconnaissance technique that proactively identifies exposed web application components, thus enabling our customers to identify and reduce attack vectors.

How Qualys WAS Fingerprints Web Applications and APIs

By scanning applications, Qualys WAS identifies and reports the exact versions of popular components and information on the application infrastructure. It passively inspects the application response, including headers, cookies, body, meta, and script tags, using pre-computed regex patterns. QID 150247 – Web Server and Technologies Detected, a unique detection identifier, lists the technologies identified during a scan.

Qualys WAS detects over 120 technologies, including AEM, AngularJS, Apache, Bootstrap, CentOS, Django, Docker, Drupal, Express, Fedora, Flask, FreeBSD, Laravel, Microsoft ASP.NET/IIS/SharePoint, Nginx, Nuxt.js, OpenSSL, PHP, Red Hat, Scientific Linux, Ubuntu, Unix, Windows Server, and more. The list does not end here…we’re always adding new technologies!

With our Out-of-Band Detection methodology, Qualys WAS minimizes false positives and negatives by detecting known vulnerabilities and common misconfigurations.

Here are some detections for Adobe Experience Manager (AEM), a popular content management system:

QID 150405Adobe Experience Manager: Set Preferences Exposed
QID 150406Adobe Experience Manager: Merge Metadata Exposed
QID 150407Adobe Experience Manager: Default Get Servlet Exposed
QID 150408Adobe Experience Manager: Query Builder Servlet Exposed
QID 150409Adobe Experience Manager: GQL Servlet Exposed
QID 150410Adobe Experience Manager: Guide Internal Submit Servlet Exposed
QID 150411Adobe Experience Manager: POST Servlet Exposed
QID 150412Adobe Experience Manager: Create JCR Nodes
QID 150414Adobe Experience Manager: Login Status Servlet ExposedQID 150415
QID 150415Adobe Experience Manager: Current User Servlet Exposed
QID 150416Adobe Experience Manager: User Info Servlet Exposed
QID 150417Adobe Experience Manager: Felix Console Exposed
QID 150418Adobe Experience Manager: WCM Debug Filter Exposed
QID 150419Adobe Experience Manager: WCM Suggestions Servlet Exposed
QID 150420Adobe Experience Manager: CRXDE Lite/CRX Exposed
QID 150421Adobe Experience Manager: Disk Usage Report Exposed
QID 150422Adobe Experience Manager: Reflected XSS via SWF
QID 150423Adobe Experience Manager: WebDAV Exposed
QID 150424Adobe Experience Manager: Groovy Console Exposed
QID 150425Adobe Experience Manager: ACS Tools Exposed
QID 150426Adobe Experience Manager: SSRF via Salesforce Secret Servlet
QID 150427Adobe Experience Manager: SSRF via Salesforce Secret Servlet
QID 150428Adobe Experience Manager: SSRF via Site Catalyst Servlet
QID 150429Adobe Experience Manager: SSRF via Auto Provisioning Servlet
QID 150430Adobe Experience Manager: SSRF via Open social

Qualys WAS Scan Configurations

Configuring Qualys WAS Scan is straightforward. In the Search Criteria pane, follow one of the methods below to scan with QID 150247:

Choose Information Disclosure:

Qualys WAS – Detection Scope Configuration – Information Disclosure Category

Make a static list of QID 150247:

Qualys WAS – Detection Scope Configuration – Custom Static Search List

In the Detection Scope configuration, select Everything. During the discovery phase, the scan detects and displays all technologies.

Qualys WAS – Detection Scope Configuration – Detect Everything

Qualys WAS Scan Report

The Qualys WAS Scan Report section allows you to analyze the report after completing the scan. When here, search for QID 150247 Web Server and Technologies Detected.

Qualys WAS – Scan Report – QID 150247

Reading the Report

QID 150247 report shows you the following information:

  • Total number of detected technologies
  • Detected technologies’ names and versions
  • For each technology, headers, HTML responses, metadata, scripts, etc., that matched
  • Identifying the first few instances of the above information, that is, the links containing the matched technology
Qualys WAS – Scan Report – QID 150247 – Results


As complex environments become more prevalent and organizations increase their use of GTM, attackers have more potential to exploit exposed web application components. As a result of our existing best practices for web application scanners (WAS), vulnerability assessments, and risk management, we provide organizations with an invaluable tool for protecting their infrastructure and reducing attack vectors.

More Information

We invite you to join us on the journey. Are you interested in trying Qualys? Register for a free trial. You can also request a demo from one of our technical account representatives. The Qualys community is also a great place to learn more about Qualys products and share your experiences.


  • Sheela Sarva, Director, Quality Engineering, Web Application Scanning, Qualys
  • Srinivas Dambal, Manager, QA Web Application Scanning, Qualys
  • Ed Arnold, Security Solutions Architect, Qualys
  • Ambika Singh, Senior Writer, Technical Content Experience, Qualys

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