If you’re a web application developer, you know how important it is to keep your apps secure. But it can be challenging to secure your app before it’s released - and new security vulnerabilities are discovered all the time.

That’s why it’s important to conduct regular web application security testing. This way, you can be sure your app isn’t vulnerable to cyber attacks or data breaches.

Authentication

Authentication is the verification of an individual's identity before they can be granted access to a protected resource or system. It can be done using something you know (login and password) or something you have (access card or key fob).

Testers use authentication to find potential vulnerabilities that could allow malicious actors to gain unauthorized access to the target application. Typically, authentication tests include user account roles and varying levels of permissions to determine whether there are any vulnerabilities that can be exploited.

When testing the security of web applications, testers also need to verify that sensitive data is stored in encrypted form. This is especially important for applications that handle billing information, 'passwords' related to the user account or any other business-critical or sensitive data.

For instance, if an attacker injects SQL statements as user inputs, they can obtain critical information from a database even if the application crashes. To mitigate this, testers must check if data is transmitted between various forms and screens only after proper encryption has been implemented, and if different'submit' actions are followed with encrypted data properly decrypted at the destination.

URL Manipulation

In web application security testing, URL manipulation is the process of changing information in a website’s URL. This is done to intercept sensitive data & credentials that are being passed between a browser and the server.

This is usually done by using the HTTP GET method to pass information between the client and the server, which is then passed through the query string. The tester then alters the query parameters to see if the server accepts it.

While this is a useful test for detecting vulnerabilities in websites, it can be used by hackers to gain access to unauthorized elements of a website. It can also allow hackers to steal confidential data, redirect users, and infect devices with malware.

The attack can occur because of a flaw in the application or malicious code being injected. It can be fixed by applying patches and updating software.

Cross-Site Scripting

Cross-site scripting (XSS) is a common web security vulnerability that allows attackers to introduce malicious JavaScript code into trusted websites. These attacks typically occur when web applications use unsafe user input directly in their HTML output without validating or encoding it.

XSS can be prevented by carefully verifying all user input and then transforming it into a safe format. However, this is not possible for every application, so web application developers must implement a variety of techniques to sanitize user input before it can be used in client-side code.

Reflected XSS is one of the most popular forms of attack. This type of XSS exploits the Hypertext Transfer Protocol response that is returned to the browser from the server.

Reflected XSS vulnerabilities can be detected through manual penetration testing or by using security tools that can automatically search for them. These XSS flaws are commonly found in web pages that allow users to input information, such as search bars or comment boxes.

SQL Injection

In web application security testing, testers must understand how an application interacts with a database server to access data. This includes authentication of web forms (checking credentials against the database) and search functions (user-submitted input can extract data from the database via SQL queries).

A SQL Injection vulnerability occurs when an application uses user input to construct SQL statements without validating or sanitizing the input before passing it to a database. This can be particularly dangerous when the application is running on a server with a compromised network or one that has been breached in the past.

In most cases, the only way to avoid an SQL injection attack is to sanitize all user input and use parameters when making queries to a database. But that is not always possible.