Software security is key to the online world’s survival. Collaborative efforts of cybersecurity professionals and volunteers have come together to create the OWASP web security testing guide. Malicious actors constantly threaten web applications, the backbone of many businesses. OWASP penetration testing is crucial for identifying and addressing these security vulnerabilities.

What is OWASP Penetration Testing?

OWASP (Open Web Application Security Project) penetration testing is a methodology focused on the vulnerabilities listed in the OWASP Top 10. This widely recognised list details the most critical web application security risks. By conducting an OWASP penetration test, organisations can proactively identify and remediate these vulnerabilities before attackers exploit them.

Given the various domains, OWASP publishes several top 10 lists, such as OWASP Top 10 web application, OWASP API Top 10, OWASP IoT Top 10, OWASP Top 10 LLM risks, etc.

Why is OWASP Penetration Testing Essential?

OWASP is a globally popular web application security project running successfully for over two decades. Here’s why OWASP penetration testing is essential for businesses:

• Reduced Security Risks: OWASP testing identifies and helps remediate vulnerabilities, significantly reducing the risk of data breaches, malware infections, and cyberattacks.
• Enhanced Compliance: Many regulations, like PCI DSS, mandate regular penetration testing. OWASP methodologies ensure compliance with these requirements.
• Improved Software Security: By identifying vulnerabilities early in the development lifecycle, OWASP testing promotes the development of more secure software.
• Strategic Security Investments: Insights gained from OWASP testing enable informed decisions about future security investments, ensuring resources are allocated effectively.

OWASP Penetration Testing Methodology

OWASP provides a comprehensive suite of methodologies for conducting penetration testing across various systems and applications. Here’s a look at the core methodologies, along with some additional approaches:

Web-based Security Testing Guide (WSTG)

• The cornerstone of OWASP testing, WSTG offers a structured framework for testing web applications.
• It outlines seven phases, guiding testers through pre-engagement, intelligence gathering, vulnerability analysis, exploitation, reporting, and remediation.

Mobile Security Testing Guide (MSTG)

• MSTG addresses the unique security concerns associated with mobile applications.
• Covers areas like platform-specific vulnerabilities, mobile device security, and attack vectors relevant to mobile apps.

Firmware Security Testing Guide

• ISTG – FW Provides a comprehensive methodology for assessing and securing firmware against vulnerabilities.
• Emphasises analysing firmware for weaknesses like insecure update mechanisms, hardcoded credentials, and inadequate encryption.

By following OWASP guidelines, organisations can identify and mitigate risks, ensuring the firmware’s integrity and protecting devices from being exploited as entry points for broader network attacks.

Beyond the Core Three:

• API Security Testing Guide: APIs (Application Programming Interfaces) are the backbone of modern interconnected systems. This guide provides a methodology for testing the security of APIs, ensuring they are not exploited to gain unauthorised access to sensitive data or functionality.
• Cloud Security Testing Guide: Cloud adoption is on the rise, but it introduces new security challenges. This guide helps organisations assess the security posture of their cloud environments, identifying vulnerabilities in cloud configurations and services.
• Internet of Things (IoT) Security Testing Guide: The ever-expanding world of IoT devices presents a unique security risk. This guide provides a methodology for testing the security of these devices, ensuring they are not exploited to disrupt operations or compromise sensitive data.

How to Perform OWASP Penetration Testing?

PTES (Penetration Testing Execution Standard) provides a structured approach for conducting OWASP penetration testing. Here’s a breakdown of the critical phases:

Pre-engagement

This phase involves defining everything that helps deliver a successful pen test.

• Define the scope of the test, including specific targets and testing goals.
• Obtain necessary permissions from stakeholders.
• Establish clear communication channels for reporting findings and updates.

Intelligence Gathering

• Gather comprehensive information about the target application:

  • Web server details (version, type)
  • Application behaviour (typical requests and responses and API endpoints)
  • Crawled data (search engine results, robots.txt)
  • Application structure (folder paths, metadata)
• Identify critical assets and potential threats.

Threat Modelling

• Create a model of the web application to identify potential security risks.
• Collaborate with system administrators and security teams to:
  • Pinpoint potential security threats.
  • Assess the likelihood of each threat materialising.

• Analyse administrator interfaces and platform configurations for weaknesses.

Vulnerability Analysis

• Actively search for vulnerabilities using a combination of:

  • Automated tools: Scan for common flaws like buffer overflows, cross-site scripting (XSS), and SQL injection.
  • Manual testing: Experienced testers uncover less apparent vulnerabilities. Tools such as OWASP ZAP Burp suite are favourites amongst manual web application penetration testers.

• Scrutinise accounts, privileges, access levels, and authentication mechanisms.

Exploitation

• Attempt to exploit identified vulnerabilities to understand their potential impact.
• Demonstrate the real-world consequences of successful exploitation.
• Document the steps taken and the data accessed during exploitation.

Reporting

• Prepare a comprehensive report detailing:
  • Discovered vulnerabilities, categorised by severity.
  • Steps taken during the exploitation phase.
  • Clear and actionable remediation recommendations.
  • Prioritised list of vulnerabilities to address.

Remediation

• Prioritise identified vulnerabilities based on severity and potential impact.
• Develop a remediation strategy that may involve:
  • Applying security patches.
  • Updating software versions.
  • Implementing additional security controls.
  • Validating compliance with regulations like PCI DSS.

Verification

• Additional security testing will be conducted to ensure that implemented fixes are effective.
• Use both manual and automated assessments to verify vulnerability remediation.
• Document the verification process and any remaining concerns.

Maintenance

• Establish ongoing security practices to maintain a secure posture:
  • Regular monitoring for new threats and vulnerabilities.
  • Security control updates to stay ahead of evolving risks.
  • Frequent vulnerability assessments are needed to identify and remediate weaknesses proactively.

OWASP Top 10 Vulnerabilities

The OWASP Top 10 is a constantly evolving list of the most critical web application security risks. By understanding these vulnerabilities, organisations can prioritise their security efforts and protect their web applications from a wide range of attacks. Here’s a closer look at the top 10 threats:

1. Injection

Attackers exploit vulnerabilities in how applications handle user input, tricking them into executing malicious code.

Example: An attacker inserts SQL code into a login form field. If the application doesn’t properly sanitise the input, the database executes the malicious code, potentially granting the attacker access to sensitive information.

2. Broken Authentication

Weaknesses in authentication mechanisms allow attackers to compromise user accounts, impersonate legitimate users, or bypass security measures entirely.

Example: An application uses weak or easily guessable passwords. An attacker could access user accounts through brute-force attacks or by exploiting stolen credentials.

3. Sensitive Data Exposure

Inadequate protection of sensitive data in storage and during transmission can lead to data breaches and privacy violations.

Example: An e-commerce website stores credit card information in plain text due to insecure design flaws. If a vulnerability allows attackers to access the database, they could steal sensitive customer data.

4. XML External Entities (XXE)

Attackers exploit vulnerabilities in XML processors to access restricted files, execute code, or launch denial-of-service attacks.

Example: An attacker sends malicious XML input containing an external entity reference to a vulnerable application. This reference points to a sensitive file on the server, which the application retrieves and processes, potentially exposing confidential data.

5. Broken Access Control

Inadequate authorisation mechanisms allow unauthorised users to access sensitive data, modify functionality, or bypass security controls.

Example: An attacker manipulates URL parameters or HTTP headers to access restricted resources, such as viewing another user’s account information or performing administrative actions without proper authorisation.

6. Security Misconfiguration

Insecure default configurations, incomplete or missing security hardening measures, and misconfigured security headers expose applications to attacks.

Example: An application server displays detailed error messages, revealing sensitive information about the server configuration or application logic. Attackers can exploit this information to identify vulnerabilities and launch targeted attacks.

7. Cross-Site Scripting (XSS)

Attackers inject malicious scripts into trusted websites. When a user visits the compromised site, the script executes in their browser, potentially stealing their session cookies, redirecting them to malicious sites, or stealing their credentials.

Example: An attacker injects a script into a comment field on a blog. When other users view the comment, the script executes in their browsers, potentially stealing their login credentials or redirecting them to a phishing site.

8. Insecure Deserialization

Attackers exploit vulnerabilities in how applications deserialise data, potentially executing arbitrary code on the server or gaining unauthorised access.

Example: An application deserialises user-supplied data without proper validation. An attacker sends malicious serialised data that, when deserialised, executes a command on the server, potentially leading to a complete system compromise.

9. Using Components with Known Vulnerabilities

Applications that rely on outdated or vulnerable third-party libraries, frameworks, or components introduce security risks that attackers can exploit.

Example: An application uses an outdated version of a JavaScript library with a known vulnerability. An attacker exploits this vulnerability to inject malicious code into the application, potentially stealing data or taking control of user sessions.

10. Insufficient Logging & Monitoring

Inadequate logging and monitoring practices hinder an organisation’s ability to detect, investigate, and respond to security incidents effectively.

Example: An application fails to log suspicious activities, such as multiple failed login attempts or unauthorised access to sensitive data. This lack of visibility prevents security teams from promptly identifying and responding to potential attacks.

By understanding the OWASP Top 10 vulnerabilities and implementing appropriate security controls, organisations can significantly reduce their risk of web application attacks and protect their sensitive data. Remember, security is an ongoing process that requires continuous vigilance, proactive measures, and a commitment to staying ahead of evolving threats.

OWASP Security Testing Tools to Use

A range of tools can be used during OWASP penetration testing, categorised as follows:

• Information Gathering Tools: These tools are used to gather information about the target system, such as network structure, open ports, and running services. Examples include Nmap for network scanning, DNSenum for DNS enumeration, and WhatWeb for website fingerprinting.
• Vulnerability Scanning Tools: These tools automate scanning for known vulnerabilities in web applications and operating systems. Popular choices include Nessus, OpenVAS, and Nikto. These scanners often have databases of known vulnerabilities and check the target system against these databases.
• Exploitation Tools: Once a vulnerability is identified, exploitation tools can be used to simulate an attack and understand the potential impact. Metasploit and Burp Suite are widely used, allowing testers to exploit vulnerabilities in a controlled environment safely.
• Web Hacking Tools: These tools are specifically designed for testing web applications. Examples include SQLmap for SQL injection testing, Burp Suite for intercepting and modifying web traffic, and OWASP ZAP for finding vulnerabilities like XSS and cross-site request forgery (CSRF).

By using a combination of these tools, penetration testers can effectively identify and exploit vulnerabilities in web applications, helping organisations improve their security posture.

Download free OWASP penetration testing checklist to improve software security

The OWASP Testing Guide is a valuable resource for conducting thorough and consistent penetration testing internally and with external vendors.

OWASP Penetration Testing Checklist can be downloaded here:

OWASP Penetration Testing Checklist

When followed, this comprehensive checklist empowers organisations to conduct thorough and effective penetration tests, identifying and addressing vulnerabilities before attackers can exploit them.

FAQs

What does OWASP stand for?

OWASP stands for Open Web Application Security Project.

Is OWASP a framework?

Not exactly. OWASP offers methodologies and resources for penetration testing but doesn’t dictate specific tools or actions.

How much does it cost to perform OWASP pentest?

OWASP pen testing costs can vary from £3500 to over £10,000 for small to large applications, depending on application size, complexity, and pentester experience.

How does OWASP help in penetration testing?

• Provides a structured approach (methodologies) to identify vulnerabilities in web applications and other systems.
• Offers a testing checklist to ensure comprehensive assessments.

What is the OWASP penetration testing kit?

There’s no single “OWASP pen testing kit,” but testers use various tools based on the project.

Does OWASP deal with only web application security?

While web security is a core focus, OWASP also offers methodologies for testing mobile apps, firmware, and cloud environments.