Summarize the risks of using JavaScript in a web application from a security perspective.

JavaScript is a “high-level, interpreted programming language” 6 that has gained immense popularity since its release in 1995. It is mostly used in the creation of dynamic web pages as it supports functionalities such as “form submission/validation, interactivity, animations, user activity tracking” 6 and more. It works by embedding a JavaScript function within the Document Object Model (DOM) of the HTML page. While this allows developers greater control over the HTML, it also poses a serious vulnerability, as hackers can deliver scripts over the web and run them on client computers.

Additionally, JavaScript supports multiple platforms web browser applications and mobile applications, and this large-scale presence magnifies the risks associated with it.

These risks are-

  • XSS

Cross-Site Scripting (XSS) enables attackers to manipulate websites to return malicious scripts to visitors. These malicious scripts can then give the attacker complete control on the client machine.
If XSS vulnerabilities aren’t remediated, they can result in “user data theft, account tampering, malware spreading or remote control over a user’s browser” 6

  • CSRF
    Cross-Site Request Forgery (CSRF) vulnerabilities allow attackers to manipulate victims’ browsers to perform malicious actions on other websites. This JavaScript security issue can lead to “account tampering, data theft, fraud” 6 and more.
  • Injections

While XSS and CSRF vulnerabilities of JavaScript pose the most risk to web and mobile applications, there are a variety of other common security issues that can increase risks for users.
These issues include “improper client-server trust relationships” 6, vulnerabilities in browser and browser plugin code, SQL Injection, Command Injection, and others.