single page application (SPA)

Charlie Fleetham

min read

What is a Single Page Application (SPA)?

A Single Page Application (SPA) is a type of web application that loads a single HTML page and dynamically updates content without requiring a full page reload. Instead of navigating from one page to another, everything happens within that one page - only the content that changes gets updated.

This makes SPAs fast and efficient for users, because they don’t need to reload static elements like headers or menus every time they click something. Modern SPAs are often built with JavaScript frameworks like React, Angular, or Vue.js.

Why are SPAs challenging to scan?

Because SPAs rely heavily on JavaScript to load content and respond to user actions, traditional vulnerability scanners may struggle to discover all the app’s content. Unlike MPAs (Multi Page Applications) where each page is directly linked, SPAs require interaction - like clicking tabs, opening dropdowns, and submitting forms - to reveal all the functionality.

Scanning SPAs often involves simulating real user behavior to fully explore the interface and find hidden security flaws.

Why scanning SPAs matters

SPAs are widely used for high-value applications, which makes them attractive targets for attackers. Regular vulnerability scanning is essential to:

Protect sensitive user data
Maintain a strong security posture
Meet compliance frameworks like ISO 27001, SOC 2, and Cyber Essentials

SPA vulnerability scanner

Platforms like Intruder are designed to handle the complexity of scanning SPAs, helping you uncover vulnerabilities across dynamic interfaces. Get started for free with a 14 day trial.