What is Web Application Security?

The Most Common Web Application Security Vulnerabilities

As web applications and APIs comprise an increasing portion of your digital attack surface, they become a bigger target for cyberattacks. This includes exploiting both known web application vulnerabilities and identifying previously unknown exploits. These are called zero-day vulnerabilities, new threats that can cause significant damage before developers find a fix and update their applications to remove the risk they pose.

The MITRE Corporation, funded by the US National Cyber Security Division, maintains a database of known information security vulnerabilities, assigning Common Vulnerabilities and Exposures (CVE) identifiers to each. Of these discovered vulnerabilities, the Open Web Application Security Project (OWASP) compiles lists of the top 10 web application security risks.

The most recent OWASP Top 10 was published in 2021, with the organization planning to release an updated version in 2025. The OWASP top 10 is intended for developers and security professionals, providing a broad consensus on the most critical vulnerabilities to be aware of. This makes it a valuable resource for understanding potential vulnerabilities in your web applications.

The current OWASP top 10 list of web application vulnerabilities includes:

• Broken Access Control: Users are able to access information without the proper permissions.

• Cryptographic Failures: Not implementing or poorly implementing data encryption.

• Injection: Failing to sanitize user inputs so that they can manipulate an app’s functionality.

• Insecure Design: Broad category covering flaws in the fundamental design of the application.

• Security Misconfigurations: Improper, incomplete, or insecure setup of the application’s security settings.

• Vulnerable and Outdated Components: Incorporating components that contain vulnerabilities or are no longer maintained.

• Identification and Authentication Failures: Inability to properly confirm a user’s identity.

• Software and Data Integrity Failures: Code and infrastructure without integrity protections.

• Security Loggings and Monitoring Failures: Not implementing the capabilities required for effective incident response.
• Server-Side Request Forgery: Returning a remote resource without validating the user-provided URL.

OWASP has also undertaken a related security project for APIs. The latest OWASP top 10 for API security risks was published in 2023.

Minimizing Risk with Web Application Security Best Practices

There is a range of methods for web developers and security professionals to prevent vulnerabilities and the attacks they enable. The web application security tools mentioned above, along with others, are key to implementing these methods and best practices.

Common web application security best practices to focus on include:

Protecting Sensitive Data with Up-to-Date Encryption Methods

Encryption, both when it’s in transit and at rest, is vital to preventing unauthorized access to your sensitive data. Choose widely accepted, strong protocols that are not susceptible to known attacks and adopt robust key management practices. Secure protocols such as TLS and SSL offer strong protection for data in transit. For data at rest, consider full disk encryption or file encryption.

Ensuring Proper Authentication and Authorization Processes are Applied

One of the most critical web application security best practices is ensuring that only approved and verified users have access to specific resources. Authentication verifies that a user is who they claim to be, and authorization determines the data to which they have access. Best practices include strong authentication methods beyond traditional passwords, such as passkeys or Multi-Factor Authentication (MFA), and access controls based on the principle of least privilege.

Sanitizing User Inputs

Many attacks, such as SQL injection and cross-site scripting (XSS), exploit web application vulnerabilities related to sanitizing and validating user input. This means using unexpected requests that manipulate the app into providing unauthorized access to data or functionality beyond normal operations. To prevent these attacks, your applications and APIs should sanitize all inputs, checking they match the expected format in terms of format, length, and data type.

Implementing Rigorous Web Application Security Testing

Web application security testing is vital to identifying vulnerabilities in the source code or misconfigurations. The goal is to test whether an application or API responds correctly even when under attack. For example, a common method of web application security testing involves sending different inputs to the software to provoke errors or cause the code to behave in an unexpected way. Specific inputs may expose vulnerabilities that bypass security controls, such as authentication and authorization measures, allowing attackers to breach your systems or force the application to return sensitive data.

There is a range of different web application security tests you can incorporate into your development cycle to catch vulnerabilities before attackers can exploit them. Examples include:

• • Dynamic Application Security Test (DAST): Automates simulated attacks in running applications to find vulnerabilities without access to the source code.

• Static Application Security Test (SAST): Scans source code to detect security flaws early in the development process before the application is deployed.

• Penetration Test: A more in-depth manual test that simulates attacks to identify complex vulnerabilities or flaws in business logic and evaluate security controls.

• Runtime Application Self-Protection (RASP): Monitors applications in real-time to automatically block or minimize the impact of attacks.

Modern DevSecOps strategies integrate web application security testing as early as possible into the development lifecycle to enhance software quality and minimize the need for security patches post-deployment.