Web application security testing is a vital part of any software development lifecycle. It helps identify vulnerabilities in applications that can be exploited by malicious hackers.

There are several types of testing techniques that can be used to secure a web app. Dynamic application security testing (DAST) and static application security testing (SAST) are two of the most popular.

Cross-site scripting (XSS)

XSS (cross-site scripting) is one of the most common vulnerabilities that affects web applications. The OWASP Top 10 report, released in 2017, lists it as the second most prevalent issue on the list, behind only SQL injection.

Regardless of the programming language used, a vulnerable website or web application will be susceptible to XSS if it fails to properly sanitize user input and transform it into a safe format before sending it to a browser. The most common way for attackers to exploit XSS vulnerabilities is by injecting crafted HTML that includes malicious JavaScript commands.

However, XSS can also occur in VBScript, ActiveX, Flash, and even CSS, with JavaScript primarily being targeted for its tight integration with most browsers. As a result, XSS is a very powerful attack vector that can cause significant damage to any web site or web application that is vulnerable to it.

The OWASP report also notes that XSS is a particularly serious issue for sites that support public use, as it can allow hackers to compromise the user’s personal information and system without their knowledge. This can include data such as session tokens, cookies, and other personal information.

Because of this, it’s essential that all developers, QA, and DevOps staff members receive appropriate training on web security and best practices for testing and patching. Additionally, website owners must educate their users on the dangers of XSS, so they’ll be more likely to take steps to prevent it.

Sanitizing input: All users should be taught that their input should never be trusted and that they should not use any type of sanitizing technique unless the application explicitly allows them to do so. This includes encoding and escaping techniques, HTML sanitizers, HttpOnly flags for cookies, and content security policies.

Using a filter to prevent XSS attacks: A simple but effective way of preventing XSS is to pass all inputted data through a filter that will identify and remove dangerous keywords from the input. This will prevent XSS-vulnerable JavaScript commands from being injected into the web server.

PT AI offers an extensive range of scanning and detection features that can be used to search for XSS vulnerabilities in your application source code. It provides a number of advanced techniques to detect XSS vulnerabilities and helps you to process results in convenient ways.

URL manipulation

URL manipulation, also known as URL rewriting, is a way for hackers to gain access to websites. They change parts of the Uniform Resource Locator (URL) in order to test for vulnerabilities and find ways to redirect users or trap them into a specific site.

Hackers often use URL manipulation to gain access to databases and other vital information in web applications. This can result in business disruption and costly remediation. It is crucial for organizations to have a thorough web application security testing process.

The first step in this process is to identify all potential risks and vulnerabilities within your system. Next, you need to create a traceability matrix to evaluate each risk and vulnerability in detail.

Once you have a list of possible vulnerabilities, it is time to implement a test plan. This test plan will be based on the identified risks and vulnerabilities, which can help you to quickly identify critical areas that require additional testing.

Some of the most common vulnerabilities are XSS injection, SQL injection and URL manipulation. Each of these attacks can have a huge impact on your web application, making it impossible for users to access important resources and data.

XSS injection is a type of attack in which a malicious user inserts HTML or client-side script into the user interface of a web application. This is typically done through hyperlinks and forms.

However, a web application can become vulnerable to XSS injection even when it doesn’t use forms or hyperlinks. Instead, it may communicate with the server via the HTTP GET method, which allows for parameters to be passed in the query string.

As a result, a security tester must verify whether or not the application allows sensitive information to be passed through the query string. They can do this by changing a parameter value in the application and observing what happens when it is sent to the server.

Another attack involves manipulating the path of an on-site link, which may allow a hacker to gain access to confidential data or bypass browser anti-XSS defenses. This can be achieved by adding a reference to a third-party resource, such as a malicious style sheet or script, in the path of an on-site link.

SQL injection

SQL injection is a technique used by hackers to exploit security vulnerabilities in web applications that use SQL databases. By executing malicious code in the database, attackers can gain access to sensitive data and manipulate the information. In the past, SQL injection has been exploited to steal personal information such as credit card numbers and passwords.

Several websites and web applications have been vulnerable to SQL injection, and it is important to perform vulnerability testing in order to ensure that no loopholes exist. A successful SQL injection attack can give an attacker complete access to all the data on a server.

While input filtering and escaping can help prevent most SQL injections, it is not enough to secure an application against this type of attack. In most cases, a SQL injection attack can only be stopped if the user-supplied input is validated against the expected data type or character set.

First-order SQL injection occurs when an application takes user input from an HTTP request and incorporates it into a SQL query in an unsafe way. In some cases, this is done by storing the data in the database before processing another HTTP request.

Second-order SQL injection (also called stored SQL injection) is a more complex form of the attack. It is more difficult to detect because the submitted values are not immediately executed but stored. This means that automated web application security scanners would not detect it.

To avoid this, developers can use parameterized queries and stored procedures in their web applications. Parameterized queries are an easy and effective way to ensure that the user-supplied input is used as data rather than code.

A second option is to sanitize the input before it is sent to the database. Using sanitization techniques such as whitelisting or blacklisting can also help to protect an application from this type of SQL injection.

Another approach is to create a list of select characters that are allowed in the user input fields and disallow them from being used in the application. This method can be effective at preventing a number of different types of attacks.

Authentication

Authentication is the process of verifying the identity of a user or process and confirming that they have the permissions to access certain resources. It includes human users, computer systems, servers, software, and APIs.

Web applications rely on authentication to protect data, servers, and other endpoints from attacks. They also use it to help users login, manage their sessions, and navigate application workflows.

For example, a marketer may have a user account that allows her to log into a company’s website to access marketing information. She only has access to the data that she is authorized to see. Similarly, a web application might store sensitive data in an encrypted database.

To protect this data, web application security testing tests the application’s ability to properly authenticate a user before granting access to certain pages and resources. The authentication can be performed through a variety of methods, including identifying and matching user accounts with the system’s database or generating an OTP (one-time password) or link to a mobile device.

If a web application’s authentication fails, it will be unable to log or audit user activity, which can make it difficult to detect attackers, uncover exploits, and learn how to prevent future attacks. This can lead to a significant increase in the time it takes for security teams to find and remediate vulnerabilities.

Another way that an attacker could leverage a flaw in authentication is to obtain administrative user privileges. This can be done by obtaining a URL that references an admin parameter or cookie. If an attacker is able to get an admin parameter or cookie, they can append that to any other URL and get access to privileged pages, functions, and information.

As mentioned earlier, web applications are the most common attack vector for cybercriminals seeking to breach databases and client systems. They are available to users 24/7 and can often be accessed through various mobile platforms.

Because of the nature of this threat, web application security testing is a key step in protecting your organization and customers from malicious hackers. It identifies security gaps and helps prevent breaches, and keeps development teams on track by identifying issues that need to be addressed.