Client-side security testing focuses on identifying vulnerabilities in the client-side components of web applications, such as browsers and user interfaces.

Below is a summary of key areas tested:

  • DOM-based Cross-Site Scripting (XSS): Tests for vulnerabilities where malicious scripts are executed directly in the browser by manipulating the Document Object Model (DOM).
  • JavaScript Execution: Evaluates unsafe JavaScript functions (e.g., eval()) that could allow arbitrary code execution.
  • HTML/CSS Injection: Checks for injection of untrusted HTML or CSS, which can manipulate the user interface or execute malicious actions.
  • Client-Side URL Redirect: Identifies unvalidated URL redirects that attackers could exploit to redirect users to malicious sites.
  • Client-Side Resource Manipulation: Tests for unauthorized modifications of resources like scripts or images loaded by the application.
  • Cross-Origin Resource Sharing (CORS): Assesses overly permissive CORS policies that might expose sensitive data to unauthorized domains.
  • Cross-Site Flashing: Reviews legacy Flash content for vulnerabilities, though this is less common due to Flash’s deprecation.
  • Clickjacking/UI Rendering: Ensures protection against UI overlay attacks using headers like X-Frame-Options or Content Security Policy.
  • Web Sockets: Validates secure implementation of WebSocket connections, ensuring proper authentication and encryption.
  • Web Messaging: Examines the use of postMessage for secure communication between browser windows or iframes.
  • Local Storage/Session Storage Sensitive Information: Audits client-side storage for improper handling of sensitive data, recommending encryption and secure management.

These tests aim to safeguard users and applications from common client-side attacks, ensuring robust security practices in web environments.