What is Web App Penetration Testing? [How to Conduct It]

Web application penetration testing involves performing a simulated attack on a web app to determine weaknesses that hackers can exploit. The testing process uses emulations of real-world attacks to identify hidden attacks such as SQL injection, cross-site scripting (XSS), or cross-site request forgery (CSRF).

What is the worst that could happen if you don’t continuously test your web application for vulnerabilities? Imagine if 4 billion private messages from 650 million of your users were leaked online. This nightmare became a harsh reality for Discord in April 2024.

Data breaches like this can severely damage your brand’s reputation and put company and customer data at risk. Web application penetration testing solves this problem by identifying vulnerabilities before hackers exploit them.

This article helps you better understand the web application penetration testing tools available, the steps involved, and the types of pen testing that can be employed.

What is Web Application Penetration Testing?

Web application penetration testing is a simulated cyberattack that systematically examines your web application’s infrastructure, design, and configurations to identify, analyze, prioritize, and mitigate vulnerabilities such as XSS attacks, SQL injections, and business logic bugs, that could potentially lead to unauthorized access or data breaches. It helps organizations comply with security standards and regulations such as PCI-DSS, HIPAA, GDPR, and SOC 2 while uncovering & mitigating security risks to improve the applications’ safety posture before they can be exploited. 

What is the Web App Penetration Testing Process?

The usual process of web app penetration testing involves a vulnerability scanner, which probes and detects loopholes in your security, such as misconfiguration, unpatched software, SQLi, cross-site scripting, etc.

1. Planning Phase

A web app pentest is begun by defining the pentest scope, timeline, and people involved. The customer company and our team of pentesting experts decide on the scope together.

Some considerations in this stage are which application pages need to be tested and whether to perform internal, external, or both testing. Defining the timeline for the whole process in this step is also crucial.

2. Reconnaissance

During the reconnaissance phase, our pentesters gather as much information as possible about the target web application and its environment. This helps tailor the testing process and identify potential weaknesses. We also perform port scanning, service identification, vulnerability assessment, and other tasks in this testing phase. 

Step 1: We begin by passively collecting publicly available information about the target using methods such as DNS enumeration to find hidden functions and web scraping to extract information about the application. 

Step 2: Our experts then move into the active reconnaissance phase, where they interact with the application to reveal weak entry points using port scanning and crawl through it to understand its functionality in detail.

Key Tools Used During Reconnaissance:

• Astra Pentest: Our pentest plans boast features like web scraping, port scanning, and scan-behind-login, while our intelligent vulnerability scanner conducts an in-depth survey of the target before the pentesting process begins.
• Nmap: Nmap is a network scanner that discovers open ports, services running on those ports, and the operating system of the target system.
• DNS Enumeration Tools: Tools like GoBuster, Aquatone, or Subfinder help identify subdomains associated with the main domain. This can expose hidden functionalities or administrative interfaces.
• Web Scraping Tools: Web application penetration testing tools like Scrapy or theHarvester can be used to obtain information about the application’s technologies, URLs, and potential API endpoints.

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3. Vulnerability Scanning

Now that we have the reconnaissance data, the next step involves using automated tools to scan for known vulnerabilities. These tools compare the application against Common Vulnerabilities and Exposures (CVEs) databases and identify potential weaknesses in code, configuration, or dependencies.

Key Tools Used During Vulnerability Scanning:

• Open-Source Scanners: Kali or Nikto are popular open-source vulnerability scanners that can identify various vulnerabilities specific to web applications, such as SQL injection and Cross-Site Scripting (XSS).
• Commercial Scanners: Scanners like Astra Pentest offer additional features like detailed reporting, integration with other security tools, remediation guidance, and a zero false positives guarantee for vetted scans.

4. Exploitation (Pentesting)

While vulnerability scanners provide a great starting point for penetration testing, manual exploitation is crucial to identifying more complex vulnerabilities and misconfigurations. 

This is an essential part of the penetration testing process, where our pentesters manually exploit the target system to find business logic vulnerabilities, look for unique attack vectors of vulnerabilities that could be very harmful when combined, and identify each vulnerability’s critical rating. 

Exploitation aims not to cause damage but to understand the potential consequences of a successful real-world attack. This allows the organization to prioritize remediation efforts accordingly. 

Exploitation involves using various tools and techniques to gain unauthorized access to the system, steal data, or disrupt operations.

Web Application Penetration Testing Examples: 

The information gathered during recon and scanning helps us plan and execute exploitation attempts. For example, an identified SQL injection vulnerability in a search form might be exploited using a tool like SQLmap to extract sensitive data from the database.

We then attempt to chain vulnerabilities together to achieve a more significant impact. For instance, a directory traversal vulnerability could be combined with a code injection flaw to upload a malicious web shell and gain remote access to the server.

Key Tools Used During Exploitation:

• Exploit Frameworks: Frameworks like Metasploit provide pre-built modules that can be used to exploit specific vulnerabilities. However, these tools require a deep understanding of the vulnerability and customization for the target application.
• Custom Scripts: For zero-day vulnerabilities or those not covered by existing tools, pentesters may develop custom scripts to exploit the vulnerability. Reputable pentest service providers constantly update their tests to account for this.
• Password Cracking Tools: Tools like JohnTheRipper can be used to crack hashed passwords obtained during the test if password spraying or other techniques fail to gain access.

5. Reporting and Remediation

Once the exploitation phase is complete, our team will provide a detailed report illustrating all the findings. This report should include:

• A description of each vulnerability identified.
• The severity of the vulnerability (based on CVSS scoring or other metrics).
• The potential impact of exploiting the vulnerability.
• Step-by-step instructions on reproducing the vulnerability (for internal remediation teams).
• Recommendations for remediation.

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What Tools are Used for Web Application Pen Testing?

• Astra Pentest
• Acunetix
• HackerOne
• Burp Suite
• Browser’s Developer Tools
• NMap
• Zenmap
• ReconDog
• Nikto

What Makes Astra the Best VAPT Solution?

• We’re the only company that combines automated & manual pentest to create a one-of-a-kind pentest platform.
• The Astra Vulnerability Scanner runs 10,000+ tests to uncover every single vulnerability
• Vetted scans ensure zero false positives.
• Our intelligent vulnerability scanner emulates hacker behavior & evolves with every pentest.
• Astra’s scanner helps you shift left by integrating with your CI/CD.
• Our platform helps you uncover, manage & fix vulnerabilities in one place.
• Trusted by the brands you trust like Agora, Spicejet, Muthoot, Dream11, etc.

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Types of Web Application Pen Testing

The types of web application pen testing can be divided based on assets, teams, and methodology. 

1. Assets in Scope:

• Black-Box Pentesting: Black-box pentesting simulates a hacker’s attack style in the closest possible way, where the tester has limited to no knowledge about the application’s internal workings, code, or architecture. They gather and leverage publicly available information about the target, which may lead to critical areas and CVEs being missed.
• White-Box Pentesting: Here, the pentester has complete access to the application’s source code, internal documentation, and infrastructure details. White-box is the most thorough of the three methods, as the attacker has complete insider knowledge. It is useful for identifying vulnerabilities specific to the application’s codebase.
• Gray-Box Pentesting: Gray-box testing lies between black-box and white-box testing. Here, the pentester has limited knowledge about the application’s functionality and architecture (for example, login credentials) but does not have full access to the source code. 

Thus, it mimics hacker behavior with a predictable timeline while compensating for the shortfalls of the other two methods.

2. Teams Involved:

• Internal Penetration Testing: Usually conducted by in-house teams, internal penetration testing is a cost-efficient analysis of your web application to identify and track common CVEs and the hacker’s lateral movement from the inside. This helps prevent attacks by exploiting vulnerabilities existing within the corporate firewall or processes.
• External Penetration Testing: Usually performed by a third-party pentest provider, external pentesting involves simulating attacks on a live website or web application using black or grey box testing methodology. 

As such, the pentester only gets the list of the organization’s IPs, domains, and login credentials to penetrate the target and uncover any blind spots the internal teams might miss. 

3. Methodology:

• Network Penetration Testing: A network pentest tests the entire network infrastructure, including the web application, to identify vulnerabilities allowing attackers to access sensitive data.
• Dynamic Application Security Testing (DAST): DAST employs automation by using scanners to interact with the application actively during testing, emulating real hacker behavior and continuously identifying vulnerabilities.
• Static Application Security Testing (SAST): SAST analyzes the application’s source code to find potential vulnerabilities and coding errors that could lead to security gaps.

Benefits of Web Application Penetration Testing

The benefits of conducting web application penetration testing include it being a cost-effective method to prevent security breaches proactively, helping you achieve compliance requirements, and more.

1. Identifying Vulnerabilities

Web app pentesting finds security gaps in your web application before they can be exploited by a hacker, ranging from SQL injection flaws to deep-rooted misconfigurations within the app. 

Once these vulnerabilities are identified, you can implement remediation steps to improve the security posture of your app.  

2. Compliance Adherence

Conduct pentesting and mitigate the security risks associated with a specific list of critical vulnerabilities to achieve compliance with PCI DSS, GDPR, SOC 2, HIPAA, and ISO27001. 

While some compliance regulations are mandated by law, compliance certification helps establish credibility and show dedication to data security in the eyes of your customers.

3. Cost-Effective Proactivity 

Investing resources into proactively eliminating security risks before your system can be exploited is comparatively very cost-effective, as it prevents the huge loss of data, money, and resources that is incurred by a data breach. 

In 2023, the average data breach cost in the USA amounted to 9.48 million USD, making it much more economical to prevent data breaches before they happen.

Should You Consider Automated or Manual Pentesting?

Why Astra?

Key Features:

• Platform: SaaS
• Pentest Capabilities: Continuous automated scans with 9300+ tests and manual pentests 
• Accuracy: Zero false positives (with vetted scans)
• Compliance Scanning: OWASP, PCI-DSS, HIPAA, ISO27001, and SOC2
• Expert Remediation Assistance: Yes
• Customizable Reports: Yes
• Publicly Verifiable Pentest Certification: Yes
• Workflow Integration: Slack, JIRA, GitHub, GitLab, Jenkins, and more
• Price: Starting at $1999/yr

Astra Security is a vulnerability assessment and penetration testing company that provides 24/7 web app pentesting services. It detects vulnerabilities using a combination of automated and manual methods. 

Astra’s vulnerability scanner conducts 10,000+ tests and adds new tests every fortnight to find zero-day vulnerabilities. It conducts in-depth checks for critical areas like payment systems and behind login pages while looking for business logic vulnerabilities. Our CXO-friendly dashboard offers real-time vulnerability tracking and facilitates collaboration with development teams directly within the platform.

Our VAPT solution helps your team with: 

1. Better security coverage for web and mobile applications, cloud infrastructure, networks, and APIs.  
2. Detection and remediation of vulnerabilities and security gaps of varying criticality. 
3. Maintenance of compliance with regulatory requirements like HIPAA, SOC2, PCI-DSS, ISO 27001, and GDPR. 
4. Shifting from DevOps to DevSecOps gives priority to security testing applications in SDLC.

Final Thoughts

Web app penetration testing is essential in the Secure Software Development Life Cycle (SDLC) and helps develop a secure and vulnerability-free web application. This ensures end-users are safe from cyber-attacks such as data theft and exposure to sensitive information. 

Understanding the steps involved in a web app pentest and the tools used in each step, how proactive security testing can help prevent the significant loss, and how it can help you choose the right web app pentesting service provider.

Web App Penetration Testing FAQ