Web Application Penetration Testing

Web application penetration tests focus specifically on the organization’s internet – facing applications like websites , web services , and custom applications . The goal is to identify vulnerabilities that could be exploited by attackers to compromise the web application or the underlying system .

Common techniques in a web application pen test include :

  • Input validation testing to identify vulnerabilities in form fields, search functions, and other user inputs.
  • Authentication testing to evaluate the strength of passwords, session management, and login processes.
  • Business logic testing to identify flaws in the application’s control flow.
  • Back – end database testing to uncover SQL injection and other database exploits.
  • Scanning application source code for common vulnerabilities.
web application penetration testing

The results of a web application pen test provide valuable insight into an application’s overall security posture and allow the organization to patch vulnerabilities , upgrade frameworks , and implement additional controls to better protect their web applications and data .

Common Web Application Vulnerabilities

Web application vulnerabilities are security flaws or weaknesses that can be exploited by attackers to gain unauthorized access, compromise user data, or disrupt the application’s functionality. Understanding common web application vulnerabilities is essential  to identify and exploit these weaknesses during a penetration test. Here are some of the most prevalent web application vulnerabilities:

  • SQL Injection (SQLi): SQL injection occurs when an attacker is able to manipulate the application’s database queries by inserting malicious SQL code. This can lead to unauthorized data disclosure, data manipulation, or even remote code execution. SQLi vulnerabilities typically arise from improper input sanitization or lack of prepared statements in the application’s code.
  • Cross-Site Scripting (XSS): Cross-Site Scripting involves injecting malicious scripts into web pages viewed by other users. This vulnerability allows attackers to execute arbitrary code on the victims’ browsers, potentially leading to session hijacking, defacement, or theft of sensitive information. XSS vulnerabilities typically arise from improper input validation and output encoding.
  • Cross-Site Request Forgery (CSRF): CSRF occurs when an attacker tricks a victim into performing unwanted actions on a web application on which the victim is authenticated. This can File Inclusion Vulnerabilities:
  • File inclusion vulnerabilities occur when an application allows the inclusion of files from external sources without proper validation. This can enable attackers to include malicious files or execute arbitrary code on the server, leading to unauthorized access, data leakage, or server compromise.
  • Command Injection: Command injection vulnerabilities arise when an application allows user-supplied input to be executed as a command by the underlying operating system. Attackers can exploit this vulnerability to execute arbitrary commands on the server, potentially leading to full system compromise.

So, why do we need penetration testing?

Well, first of all, as someone who is responsible for securing and defending a network/system, you want to find any possible paths of compromise before the bad guys do. For years we have developed and implemented many different defensive techniques (for instance, antivirus, firewalls, intrusion prevention systems [IPSs], anti-malware).

We have deployed defense-in-depth as a method to secure and defend our networks. But how do we know if those defenses really work and whether they are enough to keep out the bad guys? How valuable is the data that we are protecting, and are we protecting the right things? These are some of the questions that should be answered by a penetration test. If you build a fence around your yard with the intent of keeping your dog from getting out, maybe it only needs to be 4 feet tall. However, if your concern is not the dog getting out but an intruder getting in, then you need a different fence—one that would need to be much taller than 4 feet.

Depending on what you are protecting, you might also want razor wire on the top of the fence to deter the bad guys even more. When it comes to information security, we need to do the same type of assessments on our networks and systems. We need to determine what it is we are protecting and whether our defenses can hold up to the threats that are imposed on them.

This is where penetration testing comes in. Simply implementing a firewall, an IPS, anti-malware, a VPN, a web application firewall (WAF), and other modern security defenses isn’t enough. You also need to test their validity. And you need to do this on a regular basis. As you know, networks and systems change constantly. This means the attack surface can change as well, and when it does, you need to consider reevaluating the security posture by way of a penetration test.