Web Application Penetration Testing: A Practical Guide

What is Web Application Penetration Testing?

Web application penetration testing, also known as pentesting, simulates attacks against your web applications, to help you identify security flaws and weaknesses so they can be remediated. You can use penetration tests to detect vulnerabilities across web application components and APIs including the backend network, the database, and the source code. 

A web application penetration testing process provides a detailed report with security insights. You can use this information to prioritize threats and vulnerabilities and define a remediation strategy. 

In this article, you will learn:

• The Importance of Penetration Testing for Web Applications: Web Application Security Threats
• Types of Penetration Testing for Web Applications
• How Do You Test Web Application Security? Web Application Pentesting Checklist
• Web Application Security FAQ
  • What Tools Are Used for Web Application Penetration Testing?
  • What is a Web Application Security Assessment?

Web Application Security Threats

Penetration testing is especially important for web applications as many web applications are mission critical systems. Web applications often store sensitive data, and may directly or indirectly generate revenue. A web application breach can cause direct financial damages, negatively impact the reputation of the business, may cause the organization to violate its compliance obligations and cause significant reputation damage. 

Since web applications handle valuable data, these systems are increasingly targeted by attackers. Here are key takeaways from the ENISA Threat Landscape 2020 and PT Security Web Application Threats Report: 

• Web application attacks increased by 52% year-over-year in 2019.
• The average web application has 22 security vulnerabilities.
• One out of five vulnerabilities discovered on web applications is of high severity.
• 20% of the organizations reported that their applications services were hit daily by distributed denial of services (DDoS) attacks.
• The most common attack techniques are buffer overflow (24%), resource reduction (23%), HTTP flood (23%), Low Slow (21%), and HTTPS flood (21%).
• Security misconfigurations are the cause of 84% of all observed vulnerabilities in web applications.
• 53% of web applications suffer from cross site scripting (XSS) vulnerabilities, and 45% have broken authentication.
• 39% of sites are vulnerable to unauthorized access, and 16% of web applications provide full system access to attackers.

Types of Penetration Testing for Web Applications

When you run a pentest for web applications, there are several aspects you need to consider. These aspects determine the location and the type of attack.

Here are the main differences between external and internal pentesting:

• External pen testing—attacks the application from the outside. The test simulates how an external attacker would behave when launching an attack. You can perform an external pentest to check firewalls and servers. 
• Internal penetration testing—attacks launched from within the organization. This is typically performed through LAN connections. The goal is to identify vulnerabilities that might exist within the firewall, simulating an attack by a malicious insider.

In addition to location of the attacker, there are other aspects to consider, such as levels of access and scope of knowledge. Below are three main types of pentesting you can run:  

• Black box penetration testing—simulate attacks launched by external actors, with no prior knowledge of the targeted system. 
• Gray box penetration testing—simulates attacks launched by internal actors, with user-level access to certain systems.
• White box penetration testing—a comprehensive pentest that simulates attacks launched by someone with root-level or administrator access and knowledge. 

Related content: read our guide to penetration testing services

How Do You Test Web Application Security? Here’s a Web Application Pentesting Checklist

Web application pentesting is typically implemented in three phases: planning, exploitation, and post-execution. Below is a quick checklist for your reference. 

Here are important aspects to consider during the planning phase:

1. Define the scope of the test.
2. Provide the pentester with all needed information, including relevant documentation.
3. Determine a success criteria for your test.
4. Review any available results from previous tests, if applicable.
5. Assess and learn as much as possible about the tested environment.

Here are important aspects to consider during the exploit phase:

1. Run the test using several different roles.
2. Follow the pre-defined successes criteria and reporting procedure when discovering vulnerabilities.
3. Create a clear and detailed report, explaining the measures taken, vulnerabilities detected, and the severity of each vulnerability.

Here are important aspects to consider during the post-execution phase:

1. Provide recommendations for remediating the detected vulnerabilities.
2. Re-test to check that the discovered vulnerabilities were properly remediated.
3. Once all tests are concluded, revert all changes back to the original configuration, including proxy settings.

Web Application Security FAQ

What Tools Are Used for Web Application Penetration Testing?

There are many tools you can use for pentesting, some offer ad-hoc capabilities while others provide an end-to-end solution. Bright is an end-to-end platform that helps pen-testers automate the penetration testing process for web applications. Nmap is a tool you can use for security audits as well as network discovery. Wireshark is a popular tool that analyzes network protocols, and Metasploit is a framework you can use to create custom pentesting tools. 

Learn more in our detailed guide to penetration testing tools

What is a Web Application Security Assessment?

A web application security assessment can help you identify vulnerabilities. You can leverage this assessment to identify misconfiguration flaws, weak authentication processes, sensitive information leakages, insufficient error handling issues, and more. 

The goal of conducting web application security assessments is to discover as many vulnerabilities in advance as possible and remediate quickly. You can use this information to reduce the attack surface and achieve regulatory compliance.

Web Application Penetration Testing with Bright

Bright significantly improves the application security pen-testing progress. By providing a no-false positive, AI powered DAST solution, purpose built for modern development environments the pen-testing process can be automated and vulnerabilities can be found faster and at a lower cost. Moreover, integrating Bright into DevOps environments enables you to run DAST scans as part of your CI/CD flows to identify a broad set of known (7,000+ payloads) security vulnerabilities early in the development process. 

In addition to detecting technical vulnerabilities, Bright’s unique ability to detect business logic vulnerabilities offers broader coverage and detection that any other automated solution. 

Learn more about Bright