Web Application Security Testing Guide

Owing to the huge amount of data stored in web applications and an increase in the number of transactions on the web, proper Security Testing of Web Applications is becoming very important day-by-day.

In this tutorial, we will do a detailed study about the meaning, tools and key terms used in Website Security Testing along with its testing approach.

Let’s move ahead!!

Web Application Security Testing

What is Security Testing?

Security Testing is a process that checks whether the confidential data stays confidential or not (i.e., it is not exposed to individuals/entities for which it is not meant) and the users can perform only those tasks that they are authorized to perform.

For Example, a user should not be able to deny the functionality of the website to other users or a user should not be able to change the functionality of the web application in an unintended way, etc.

Some Key Terms Used in Security Testing

Before we proceed further, it would be useful to familiarize ourselves with a few terms that are frequently used in web application Security Testing.

What is “Vulnerability”?

This is a weakness in the web application. The cause of such “weakness” can be due to the bugs in the application, an injection (SQL/ script code), or the presence of viruses.

What is “URL Manipulation”?

Some web applications communicate additional information between the client (browser) and the server in the URL. Changing some information in the URL may sometimes lead to unintended behavior by the server and this is termed URL Manipulation.

What is “SQL injection”?

This is the process of inserting SQL statements through the web application user interface into some query that is then executed by the server.

What is “XSS (Cross-Site Scripting)”?

When a user inserts HTML/ client-side script in the user interface of a web application, this insertion is visible to other users and it is termed XSS.

What is “Spoofing”?

Spoofing is the creation of hoax look-alike websites and emails.

Recommended Security Testing Tools

#1) Acunetix

Acunetix Banner

Acunetix is an end-to-end web application security scanner. This will give you a 360-degree view of the security of your organization. It is capable of detecting 6500 types of vulnerabilities like SQL injections, XSS, Weak Passwords, etc. It makes use of advanced macro recording technology for scanning complex multi-level forms.

The platform is intuitive and easy to use. You can schedule and prioritize full scans as well as incremental scans. It contains a built-in vulnerability management functionality. With the help of CI tools like Jenkins, new builds can be scanned automatically.

#2) Invicti (formerly Netsparker)

Invicti Banner

Invicti (formerly Netsparker) is a platform for all web application security testing requirements. This web vulnerability scanning solution has capabilities of vulnerability scanning, vulnerability assessment, and vulnerability management.

Invicti is best for scanning precision and unique asset discovery technology. It can be integrated with popular issue management and CI/CD applications.

Invicti provides proof of exploit on the identification of vulnerability to confirm that it is not a false positive. It has an advanced scanning engine, advanced crawling authentication features, and WAF integration functionality, etc. With this tool, you will get detailed scanned results with insights on vulnerability.

Security Testing Approach

In order to perform a useful security test of a web application, the security tester should have good knowledge of the HTTP protocol. It is important to have an understanding of how the client (browser) and the server communicate using HTTP.

Additionally, the tester should at least know the basics of SQL injection and XSS.

Hopefully, the number of security defects present in the web application will not be high. However, being capable of describing all the security defects accurately with all the required details will definitely help.

Methods For Web Security Testing

#1) Password Cracking

The security testing on a Web Application can be kicked off by “Password Cracking”. In order to log in to the private areas of the application, one can either guess a username/ password or use some password cracker tool for the same. A list of common usernames and passwords is available along with open-source password crackers.

If the web application does not enforce a complex password (For Example, with alphabets, numbers, and special characters or with at least a required number of characters), it may not take very long to crack the username and password.

If a username or password is stored in cookies without being encrypted, then an attacker can use different methods to steal the cookies and the information stored in the cookies like username and password.

For more details, see an article on “Website Cookie Testing”.

#2) URL Manipulation Through HTTP GET Methods

A tester should check whether the application passes important information in the query string or not. This happens when the application uses the HTTP GET method to pass information between the client and the server.

The information is passed through the parameters in the query string. The tester can modify a parameter value in the query string to check if the server accepts it.

Via HTTP GET request user information is passed to the server for authentication or fetching data. The attacker can manipulate every input variable passed from this GET request to a server in order to get the required information or to corrupt the data. In such conditions, any unusual behavior by the application or web server is the doorway for the attacker to get into an application.

#3) SQL Injection

The next factor that should be checked is SQL Injection. Entering a single quote (‘) in any textbox should be rejected by the application. Instead, if the tester encounters a database error, it means that the user input is inserted in some query which is then executed by an application. In such a case, the application is vulnerable to SQL injection.

SQL injection attacks are very critical as an attacker can get vital information from the server database. To check SQL injection entry points into your web application, find out the code from your codebase where direct MySQL queries are executed on the database by accepting some user inputs.

If the user input data is crafted in SQL queries to query the database, an attacker can inject SQL statements or part of the SQL statements as user inputs to extract vital information from a database.

Even if an attacker is successful in crashing the application, from the SQL query error shown on a browser, the attacker can get the information they are looking for. Special characters from the user inputs should be handled/escaped properly in such cases.

#4) Cross-Site Scripting (XSS)

A tester should additionally check the web application for XSS (Cross-site scripting). Any HTML For Example, <HTML> or any script For Example, <SCRIPT> should not be accepted by the application. If it is, then the application can be prone to an attack by Cross-Site Scripting.

The attacker can use this method to execute a malicious script or URL on the victim’s browser. Using cross-site scripting, an attacker can use scripts like JavaScript to steal user cookies and information stored in the cookies.

Many web applications get some useful information and pass this information on to some variables from different pages.

For Example, http://www.examplesite.com/index.php?userid=123&query=xyz

The attacker can easily pass on some malicious input or <script> as a ‘&query’ parameter which can explore important user/server data on the browser.

Important: During security testing, the tester should be very careful and should not modify any of the following:

  •  Configuration of the application or the server.
  •  Services running on the server.
  •  Existing user or customer data hosted by the application.

Additionally, a security test should be avoided in a production system.


The purpose of a security test is to discover the vulnerabilities of the web application so that the developers can remove these vulnerabilities from the application and make the web application as well as its data safe from any unauthorized action.

Recommended Reading =>Difference between SAST/DAST/IAST/RASP

Feel free to share your comments/suggestions about this tutorial.

Recommended Reading

182 thoughts on “Web Application Security Testing Guide”

  1. accurate information,simple and more understanding…kepedup man

  2. Fantastic article for the beginners, I have no basic knowledge on testing but these page made me to understand

  3. can u please provide the step by step of security testing, regarding security testing of the web application with an example. I think theoretical explanation is not enough for security testing.

  4. Excellent article.. Simple and informative..

  5. Hi ,

    Great article btw I’m a tester and I want to learn more and more about security testing… can you help me?

  6. Thanks Inder P singh,

    Nice article , I would like to know how to perform the security testing of Webservices , Restful API’s and JMS services. Can you share me the steps and tools which can be used to do that.

    My email Id :varhekarhemant@yahoo.com


  7. Very helpful article for beginners…Thanks for putting up this information here
    can u please provide the step by step of security testing, regarding security testing of the web application with an example. I think theoretical explanation is not enough for security testing.

    Also any PPT on the same would be of great advantage.

    email Id – dhingra.avika@gmail.com

    Thanks for your help in Advance!

  8. A very nice article, folks please visit OWASP top 10 vulnerabilities to get more kick out of it.

    Good Luck.

  9. You can also get OWASP Testing Guide V4.0, which has indept coverage of all that is security testing. It is under creative commons licence so is free to download and distribute.

    Good Luck.

  10. Very Nice and helpful article!!!!!!!!!!!!1

  11. hi, can anyone pls suggest me the training institutes for WAST in hyderabad or banglore. or any real time training experts.

  12. hi, what are the requisites for WEB APPLICATION SECURITY TESTING.
    ETHICAL HACKING or any other.

  13. I’m really very impressed from this website i have learnt a lot from here, you guys are one of the reason that i’m continuing my journey from an internee to Team Lead.


  14. please help me from where i can start the security testing for web application? which tool would be better? please guide me.

  15. Gr8 article.
    Please share some information about automation of security testing.

  16. Hi Guys,

    I’m very new to this field, so far i understand what is cloud testing, i have take over a task to do a web, android and ios cloud testing. Is there anyone can guide me what type of requirement we need to find a good software for this

  17. please give me solution ..

    we have web based application , some unauthorised user access our application and login to application.. how to test those ?

  18. Very useful article
    Request you to share a article for mobile application Security Testing.

  19. Hi,
    I have 1+ year experience in automation. Want to learn Security testing from sketch. Please guide me with the same and would appreciate if could be provided with some notes.

    Thanks and regards

  20. Can anyone please provide me with Sample URL’s to use for security testing with ZAP.

  21. i could not found temp folder in my computer in C drive for cookies base testing ..will you help me out to see this..

  22. Good article and excellent way to articulate, keep it up

  23. anyone here can help me? Let say Zalada website is serve through https, can anyone guide me steps on how to downgrade it to http so that a hacker can intercept and do man in the middle attack on specific user? For example, using this exploit to obtain Carol Danvers credential

  24. Hi, Thank you for sharing this Beautiful Blog…

  25. I’m really well inspired from this website . Taking up the challenge and looking forward to make blogs like this.

  26. Hii , Nice blog article , Thanks for sharing , Felt intrested to read

  27. Thanks for sharing us this beautiful article

  28. Nice Article very glad to read your Article

    Thanks & Regards


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