Web applications and websites are an integral part of modern businesses.

With the advancement in technology, especially in web-based applications, JavaScript has become a staple, but like all technologies, it comes with its set of vulnerabilities.

We delve deep into JavaScript security, its vulnerabilities, common attacks, and tools & solutions that can be implemented to ensure a safe environment for web applications.

JavaScript, a text-based programming language, primarily facilitates enhanced web functionalities like form validation, animations, videos, and other interactive elements. It's one of the core web technologies, alongside CSS and HTML.

Since its inception in 1995 by Netscape, its popularity has surged, making its presence felt on a whopping 98% of global websites, and, frameworks like Node.js have extended its use to mobile applications and server-side development.

JavaScript environments, by default, lack a built-in security permissions model, rendering them susceptible to malicious entities.

While browsers have incorporated security permissions as per the W3C standard, the responsibility of managing these falls squarely on the shoulders of website owners.

This vulnerability is further accentuated when one considers that most JavaScript in web apps originates from open-source or third-party libraries, which often come with their set of vulnerabilities.

Vulnerabilities in JavaScript often infiltrate web apps in a variety of ways. Sometimes, coding errors from well-meaning staff members can inadvertently create weak spots.

In other instances, the very source code that web applications rely upon, whether from open-source platforms or third-party libraries, may come laced with flaws or malicious intent. And then, there are the more sinister threats, where cybercriminals intentionally manipulate JavaScript code, allowing them to exploit web applications and gather sensitive data.

Thus, JavaScript vulnerabilities find their way into web apps in three ways:

• Internal JavaScript Coding Errors: Sometimes, inadvertent code additions by staff members can open vulnerabilities, leading to potential data breaches.
  
  

• Flawed Code via JavaScript Supply Chain: Web applications often incorporate code from diverse sources, including third-party libraries. Any flaw in this source code heightens the risk of a cyber-attack.
  
  

• Intentional Code Alterations by Threat Actors: Cybercriminals, by manipulating JavaScript code, can exploit web applications, pilfering sensitive data in the process.
  

Given this backdrop, the cyber landscape has witnessed a proliferation of JavaScript-centric attacks. JavaScript's susceptibility has given rise to a variety of cyber-attacks:

• E-skimming: This involves skimming user information from web pages, often from e-commerce sites.
  
  

• Formjacking: Here, malicious code is inserted into websites, hijacking their form functionalities to siphon off user data.
  
  

• Magecart: This attack aims at extracting payment information from commercial websites.
  
  

• JavaScript Injection: Malicious code is directly injected into front-end JavaScript to exploit the application and gather sensitive data.
  
  

• JavaScript Sniffers: Primarily malware designed to poach transactional data from e-commerce sites.
  

Among the various attack vectors, Cross-Site Scripting warrants a special mention. XSS attacks happen when malicious scripts are injected into websites, which are then executed by unsuspecting users' browsers. There are different types of XSS attacks:

• Stored XSS: The malicious script injected by the attacker is permanently stored on the target server.
  
  

• Reflected XSS: The user unknowingly sends a malicious script to a web server via a URL.
  
  

• DOM-based XSS: The client-side scripts in a web page modify the DOM and execute the attacker's payload.

These attacks can lead to stolen session cookies, defacement of websites, or distribution of malware.

But all is not bleak. The digital world is replete with tools and solutions to bolster JavaScript security. Web Application Firewalls (WAF) stand as sentinels ahead of web applications, rigorously scanning bidirectional web traffic to root out malicious entities.

Then there's the Content Security Policy (CSP), a robust framework that aids businesses in detecting and thwarting client-side attacks.

Penetration testing, vulnerability scanning, code scramblers, and obfuscators further add layers of security, each addressing specific vulnerabilities.

Emerging technologies like client-side attack surface monitoring offer real-time insights into a company's web assets, while JavaScript security permission technologies fortify JavaScript by continuously monitoring and blocking unauthorized scripts.

Beyond the tools and solutions mentioned, continuous education remains key. Regular training sessions for developers can equip them with the knowledge to write secure code.

Emphasizing secure coding practices and staying updated on the latest threats can significantly reduce vulnerabilities.

Additionally, employing a dedicated security team or partnering with cybersecurity firms can provide ongoing surveillance, ensuring that web assets remain protected.