Top 7 Web App Vulnerabilities and How to Prevent Them
Published at March 14, 2023

As the popularity of using web applications in modern times increases, so does the increase in web application vulnerabilities. In light of this, web application vulnerability assessment has become increasingly important. Vulnerability assessment involves identifying and prioritising vulnerabilities to increase the security of web applications.

The consequences of web application vulnerabilities can be severe. According to IBM, a data breach in 2022 cost companies globally $4.35 million, while in the US $9.44M. Data breaches resulting from web application vulnerabilities can lead to financial losses and reputational damage for companies.

Cyber attackers often target web applications to gain unauthorised access or steal sensitive data. In many cases, the impact of a web application vulnerability can extend beyond the affected organisation to its customers and partners.

As cyber threats continue to evolve, web application vulnerability prevention must keep pace. Prevention is key to protecting web applications from vulnerabilities. One of the best practices for preventing web application vulnerabilities is conducting regular vulnerability assessments. Companies should implement security controls to minimise the risks of web application vulnerabilities.

In this article, we will explore the definition of a web app vulnerability, the top 7 web application vulnerabilities and ways to prevent them. By taking proactive measures to prevent web application vulnerabilities, organisations can avoid these negative consequences.

What is a web app vulnerability?

According to Rapid7, web application vulnerabilities refer to problems or weaknesses in web-based applications that can be exploited by attackers to gain unauthorised access to the system. These vulnerabilities are usually caused by several factors such as improper validation, poorly configured web servers, or design flaws in the application. When these vulnerabilities are exploited, they can compromise the security of web applications, making it easier for attackers to access sensitive data.

It's important to note that web app vulnerabilities are different from other types of vulnerabilities. The reason for this is that web applications have to interact with multiple users across various networks, which makes them more vulnerable to attacks. This accessibility makes it easier for hackers to exploit any system flaw or weakness in the application, making it critical to take preventive measures to ensure the security of web applications.

7 Most Common Web Application Vulnerabilities and How to Prevent Them

ThirdRock Techkno outlined the most critical web application vulnerabilities. Below, we'll briefly discuss the seven most common that attackers attempt to exploit.

1. SQL Injection

SQL injection is a type of attack that targets web applications by inserting harmful SQL code into a vulnerable application. This attack can give unauthorised access to the database to attackers.

To protect your web application from SQL injection attacks, you can take a few precautions:

  • Use parameterised queries or prepared statements to prevent attackers from adding SQL code.
  • Check and clean any user inputs that could be used to run SQL commands. This way, attackers won't be able to use these inputs to gain access to the database.

2. Cross-site Scripting (XSS) 

Cross-site Scripting (XSS) is a type of web application vulnerability in which attackers add harmful scripts to a webpage that can run in the user's browser.

To prevent XSS attacks on your web application, you can follow these steps:

  • Use input validation and output encoding to stop attackers from inserting scripts.
  • Set up a Content Security Policy (CSP) that controls what type of content can be executed on a webpage. This can help reduce the risk of malicious scripts being run on your web application.

3. Clickjacking Attacks

Clickjacking is a type of attack where an attacker tricks a user into clicking a button or link on a different page according to OWASP. They do this by using transparent layers that cover up the real button or link. This can lead the user to click on the attacker's link instead of the intended one. The attacker then takes control of the user's clicks and sends them to a different page, which may be owned by another application or domain. This type of attack is also known as a "UI redress attack".

To prevent clickjacking, there are three primary methods you can use:

  1. Use Content Security Policy (CSP) frame-ancestors directive response headers to instruct the browser to avoid framing from other domains. X-Frame-Options HTTP headers can be used as a fallback for older browsers.
  2. Set authentication cookies with SameSite=Strict (or Lax) to prevent unauthorised access. Only use None if necessary.
  3. Include defensive code in the user interface to make sure that the current frame is the top-level window. This can help reduce the risk of clickjacking attacks.

4. Authentication and Session Management

Authentication and session management are very important parts of web application security. They make sure that only authorised users can use the application and that their sessions are managed correctly.

To protect your web application from authentication and session management problems, you can do the following:

  • Use strong passwords and multi-factor authentication to stop unauthorised access to your application.
  • Use secure session management techniques, such as ending sessions after a specific time or logging out users when they are inactive for a certain amount of time.

5. Broken Access Controls

Broken access controls happen when an attacker is able to get into a system without the proper security checks. This can give them access to important data or features that they shouldn't have access to.

To protect your web application from broken access controls, you should:

  • Only give users access to what they need. This is called the principle of least privilege. If users don't need access to something, don't give it to them.
  • Make sure that users are only allowed to do what they are supposed to do. This is called an authorisation check. By doing this, you can prevent attackers from doing things they shouldn't be doing.

6. Inadequate Logging and Monitoring

Not keeping enough logging and monitoring can make it hard to notice and fix security problems. To protect your web application from this issue, you can:

  • Set up a system to keep track of and analyse security events.
  • Look at these records often to quickly find and fix security problems.

7. Poor Security Testing

Poor and insufficient testing of web applications can lead to security weaknesses going unnoticed and a mistaken belief that everything is safe.

To protect your web application from these problems, you can:

  • Do security testing and analysis frequently to find and fix vulnerabilities.
  • Use tools that automatically test for common web application problems to help you find and fix issues.


In conclusion, web application vulnerabilities are a real threat that can compromise the security of your application and your users' data. However, with the right knowledge and approach, you can protect your web applications from the most common vulnerabilities. By implementing the preventative measures discussed in this article, you can minimise the risk of security breaches and ensure that your web application remains secure and trustworthy. Contact VirtualSpirit now to assist you in building a web app to foster your business!

Check Other Related Posts
This post talks about the importance of browser compatibility and cross-browser testing in front-end development.
March 23, 2023
Improve your website performance with these 6 front-end optimization techniques.
March 22, 2023
Keep your data safe from cyber threats with blockchain's secure and decentralised data storage.
March 21, 2023
View All Insights