27 Jan, 2023

Business logic flow

Vulnerability Assessment as a Service (VAaaS)

Tests systems and applications for vulnerabilities to address weaknesses.

A business logic flow vulnerability is a type of vulnerability that occurs when an attacker is able to manipulate the normal flow of a business process in order to gain unauthorized access or perform malicious actions. This can occur due to poor design or implementation of the business logic, or through the exploitation of software vulnerabilities in the underlying systems. A common example of this would be an attacker exploiting a weakness in an e-commerce platform’s ordering system to place a large number of fraudulent orders.

Examples of business logic flow vulnerability

Business logic flow vulnerabilities refer to weaknesses in the way a web application’s business logic is implemented, which can be exploited by attackers to gain unauthorized access or perform actions that they should not be able to. Some examples of business logic flow vulnerabilities include:

Injection of extra steps: Attackers can manipulate the application’s logic by injecting additional steps or bypassing certain steps altogether, such as skipping authentication or authorization checks.

Tampering with parameters: Attackers can manipulate the parameters passed to the application’s functions to change their behavior, such as altering the intended recipient of a transaction or the amount of money involved.

Forced browsing: Attackers can use links or forms to force the application to perform actions that it should not, such as allowing unauthorized access to sensitive data or executing unintended transactions.

Misuse of functionality: Attackers can exploit functionality that is intended for legitimate use in order to perform unauthorized actions, such as using a search function to extract sensitive data from the application’s database.

Improper error handling: Attackers can exploit weaknesses in the way the application handles errors to gain unauthorized access or perform unintended actions.

Here are examples of business logic flow vulnerabilities in different programming languages:

• JavaScript:

				
					var page = req.query.page;
if (page === "admin") {
  res.render("admin.ejs");
} else {
  res.render("user.ejs");
}

				
			

A vulnerability in a web application where user input is used to determine which page to display without proper validation could allow an attacker to navigate to unauthorized pages.

• Java:

				
					String function = request.getParameter("function");
if (function.equals("create")) {
  create();
} else if (function.equals("read")) {
  read();
} else if (function.equals("update")) {
  update();
} else if (function.equals("delete")) {
  delete();
}

				
			

A vulnerability in a Java web application where user input is used to determine which business function to call without proper validation could allow an attacker to execute unauthorized functions.

• C#:

				
					string table = Request.QueryString["table"];
string query = "SELECT * FROM " + table;
SqlCommand cmd = new SqlCommand(query, con);

				
			

A vulnerability in a C# web application where user input is used to determine which database table to query without proper validation could allow an attacker to read sensitive information.

Privilege escalation techniques

Privilege escalation through business logic flow vulnerability occurs when an attacker is able to exploit a weakness in the application’s logic to gain access to restricted functionality or data. This can be done by manipulating input data, intercepting network traffic, or exploiting other types of vulnerabilities.

Some common techniques for exploiting business logic flow vulnerabilities include:

  • Input validation bypass: manipulating input data to bypass validation checks and gain access to restricted functionality or data.

  • Session hijacking: intercepting and manipulating session cookies to gain access to a user’s account.

  • Parameter tampering: manipulating parameters in a URL or form data to gain access to restricted functionality or data.

  • Direct object reference: exploiting weaknesses in the application’s object-relational mapping to gain access to restricted data.

  • Race condition: exploiting timing discrepancies in the application’s logic to gain access to restricted functionality or data.

  • Command injection: injecting malicious commands into input fields to execute arbitrary code on the server.

  • File inclusion vulnerabilities: manipulating input data to include external files and execute arbitrary code on the server.

  • File upload vulnerabilities: uploading malicious files that can be executed on the server.

General methodology and checklist for business logic flow vulnerability

  1. Understand the application: Understand the functionality and data flow of the application to identify potential areas of weakness.

  2. Perform reconnaissance: Gather information about the application, such as the technologies it uses and the URLs and parameters it accepts.

  3. Test input validation: Attempt to bypass input validation controls by manipulating input data.

  4. Test session management: Attempt to hijack sessions by intercepting and manipulating cookies.

  5. Test parameter tampering: Attempt to manipulate parameters in URLs and form data to gain access to restricted functionality or data.

  6. Test direct object reference: Attempt to exploit weaknesses in the application’s object-relational mapping to gain access to restricted data.

  7. Test for race conditions: Attempt to exploit timing discrepancies in the application’s logic to gain access to restricted functionality or data.

  8. Test for command injection: Attempt to inject malicious commands into input fields to execute arbitrary code on the server.

  9. Test for file inclusion vulnerabilities: Attempt to manipulate input data to include external files and execute arbitrary code on the server.

  10. Test for file upload vulnerabilities: Attempt to upload malicious files that can be executed on the server.

  11. Test for authentication and authorization controls: Attempt to bypass authentication and authorization controls to gain access to restricted functionality or data.

  12. Test for error handling: Attempt to exploit weaknesses in the application’s error handling to gain access to restricted functionality or data.

  13. Test for privilege escalation: Attempt to escalate privileges by exploiting weaknesses in the application’s logic.

  14. Review and report: Review the results of the testing, document any vulnerabilities found, and report them to the appropriate parties.

It’s important to note that this is not an exhaustive list and depending on the application, there may be other areas that should be tested. Additionally, it’s important to always follow ethical hacking standards and guidelines while performing the testing.

Tools set for exploiting

  • Burp Suite: A popular tool for web application security testing, which includes a proxy, scanner, and intruder.

  • OWASP ZAP: An open-source web application security scanner that can be used to identify vulnerabilities in web applications.

  • Nmap: A network exploration and security auditing tool that can be used to identify open ports and services on a target system.

  • Metasploit: A framework for developing and executing exploit code, which can be used to identify and exploit vulnerabilities in systems and applications.

  • Nessus: A vulnerability scanner that can be used to identify vulnerabilities in systems and applications.

  • Aircrack-ng: A wireless network security tool that can be used to crack wireless encryption keys and perform wireless penetration testing.

  • sqlmap: An open-source tool for detecting and exploiting SQL injection vulnerabilities.

  • w3af: An open-source web application security scanner that can be used to identify vulnerabilities in web applications.

  • Maltego: A tool for data mining and link analysis that can be used to identify relationships between data.

  • John the Ripper: A password cracking tool that can be used to crack password hashes.

  • Cain and Abel: A tool for password cracking and network sniffing.

  • Wireshark: A network protocol analyzer that can be used to capture and analyze network traffic.

  • Fiddler: A web debugging proxy tool that can be used to capture and analyze web traffic.

  • Snort: An open-source intrusion detection system that can be used to detect network-based attacks.

  • Immunity Debugger: A powerful debugger that can be used to analyze and exploit vulnerabilities in software.

  • Core Impact: A commercial penetration testing tool that can be used to identify and exploit vulnerabilities in systems and applications.

  • BeEF: A browser exploitation framework that can be used to exploit vulnerabilities in web browsers.

  • Nikto: An open-source web server scanner that can be used to identify vulnerabilities in web servers.

  • sqlninja: A tool for exploiting SQL injection vulnerabilities in Microsoft SQL servers.

  • Vega: An open-source web security scanner that can be used to identify vulnerabilities in web applications.

This is not an exhaustive list, and there are many other tools that can be used for attack depending on the scope of the assessment and the system being tested.

Top CVES

• CVE-2019-0708: A vulnerability in Microsoft Windows Remote Desktop Services that could allow an attacker to execute code on the affected system without authentication. This vulnerability, known as BlueKeep, had a CVSS base score of 9.8.

• CVE-2017-5638: A vulnerability in Apache Struts 2 that could allow an attacker to execute arbitrary code on the affected system. This vulnerability had a CVSS base score of 9.8.

• CVE-2020-0601: A vulnerability in the Windows CryptoAPI that could allow an attacker to spoof digital certificates and execute arbitrary code on the affected system. This vulnerability had a CVSS base score of 9.8.

• CVE-2018-0101: A vulnerability in Cisco ASA Software that could allow an attacker to execute arbitrary code or cause a denial of service (DoS) on the affected system. This vulnerability had a CVSS base score of 9.8.

• CVE-2020-0796: A vulnerability in Microsoft Windows SMBv3 that could allow an attacker to execute arbitrary code on the affected system without authentication. This vulnerability, known as SMBGhost, had a CVSS base score of 10.

Business logic flow vulnerability exploits

  • EternalBlue: An exploit that was developed by the National Security Agency (NSA) and leaked in 2017, which targets a vulnerability in Microsoft Windows SMBv1 and can be used to execute arbitrary code on the affected system.

  • WannaCry: A ransomware attack that spread rapidly using the EternalBlue exploit in 2017, affecting hundreds of thousands of systems worldwide.

  • Metasploit: An open-source framework that can be used to develop and execute exploit code, which can be used to exploit a wide range of vulnerabilities in systems and applications.

  • Heartbleed: A vulnerability in the OpenSSL library that allows an attacker to read the memory of the affected system, potentially leading to the disclosure of sensitive information.

  • Stuxnet: A sophisticated piece of malware that was designed to target industrial control systems, specifically those used in nuclear facilities in Iran.

  • Shellshock: A vulnerability in the Bash shell that could be used to execute arbitrary code on the affected system.

  • Spectre and Meltdown: Two vulnerabilities that affect modern processors and can be used to read sensitive information from the affected system.

  • Petya: Ransomware attack that spread rapidly in 2016-2017 that encrypts the hard drive’s master file table (MFT) making the system unbootable

  • BlueKeep: A vulnerability in Microsoft Windows Remote Desktop Services that could allow an attacker to execute code on the affected system without authentication.

  • Ghostcat: A vulnerability in Apache Tomcat that could allow an attacker to read or write files on the affected system.

Practicing in test

Business logic flow vulnerabilities can be tested in different areas of an application, including:

  1. User Input: Testing for vulnerabilities in the application’s input validation and filtering mechanisms.

  2. Authentication and Authorization: Testing for vulnerabilities in the application’s authentication and authorization mechanisms, such as bypassing login or gaining unauthorized access to restricted functionality.

  3. Data storage and handling: Testing for vulnerabilities in the application’s data storage and handling mechanisms, such as SQL injection or insecure data storage.

  4. Business logic: Testing the application’s business logic and flow, such as manipulating input to access restricted functionality or bypassing business rules.

  5. API :Testing the API endpoints for potential vulnerabilities that could be exploited to access restricted functionality or data.

These tests can be performed manually or by using automated tools, such as web vulnerability scanners. Additionally, code review and threat modeling can also be used to identify and test for business logic flow vulnerabilities.

For study business logic flow vulnerability

  1. Courses: There are several online courses that cover topics related to business logic flow vulnerabilities, such as “Web Application Penetration Testing” and “Secure Coding in Java.”

  2. Practice: Websites like HackerOne and Bugcrowd offer platforms where you can practice identifying and reporting vulnerabilities in real-world web applications.

  3. Videos: There are a number of informative videos on YouTube that discuss business logic flow vulnerabilities and how to find them. Some popular channels to check out include:

• OWASP
• SANS Institute
• PortSwigger Web Security
• HackerOne
• Bugcrowd

  1. Books: You can also find books on the subject of web application security and penetration testing, which will cover business logic flow vulnerabilities and how to identify and prevent them.

  2. Websites: Websites like OWASP (Open Web Application Security Project) have a wealth of information on web application security and business logic flow vulnerabilities.

List of payloads

  • Injection of unexpected input data: Attempting to input unexpected data, such as special characters or SQL injection strings, into a system to see how it handles the input and potentially exploit any vulnerabilities.

  • Manipulation of session variables: Attempting to manipulate session variables, such as user credentials or permissions, to gain unauthorized access to the system.

  • Bypassing input validation: Attempting to bypass input validation controls, such as form fields or filters, to submit malicious data to the system.

  • Exploiting known vulnerabilities: Attempting to exploit known vulnerabilities, such as those listed in the Common Vulnerabilities and Exposures (CVE) database, in the system’s software or hardware.

  • Exploiting misconfigurations: Attempting to exploit misconfigurations in the system, such as weak passwords or insecure network protocols, to gain unauthorized access.

  • Social Engineering: Attempting to trick users into performing actions that could lead to a vulnerability exploitation such as phishing, baiting, or pretexting.

How to be protected from business logic flow vulnerability

To block or stop business logic flow vulnerability, you can use Sigma rules or firewall rules that can detect and prevent malicious activity. Some examples include:

  1. Detect and block attempts to access restricted resources or areas of the system that are not intended for public access.

  2. Monitor for and block attempts to manipulate or bypass business logic controls, such as input validation or access controls.

  3. Identify and block attempts to perform actions that are not authorized, such as modifying data or executing code without proper permissions.

  4. Inspect network traffic to detect and prevent attacks that exploit known vulnerabilities in business logic, such as SQL injection or cross-site scripting (XSS) attacks.

  5. Regularly update the system with the latest security patches and perform regular security assessments to identify and mitigate vulnerabilities.

Mitigations

Here are some examples of mitigations for business logic flow vulnerability, numbered for your convenience:

  1. Implement input validation and sanitization to ensure that any data entered by users is properly formatted and does not contain any malicious code.

  2. Use access controls to restrict access to sensitive resources and areas of the system to only those users who are authorized.

  3. Perform regular security assessments to identify and address any vulnerabilities in the system’s business logic.

  4. Implement logging and monitoring to detect and respond to any suspicious activity or unauthorized access to the system.

  5. Regularly update the system with the latest security patches and software.

  6. Use of secure coding practices when developing business logic code and web applications to prevent common vulnerabilities such as SQL injection, XSS, and CSRF

  7. Use of security testing tools to test the business logic code and web applications for vulnerabilities during the development process

  8. Use of security best practices to design and implement business logic

  9. Use of a web application firewall (WAF) to protect the web applications against known and unknown vulnerabilities.

  10. Train employees and developers on security best practices and the importance of following secure coding practices.

Conclusion

In conclusion, business logic flow vulnerability is a type of security vulnerability that can occur when there are weaknesses or flaws in the way a system’s business logic is implemented. These vulnerabilities can be exploited by attackers to gain unauthorized access to sensitive resources, manipulate data, or perform other malicious actions. To mitigate these vulnerabilities, it is important to implement security controls such as input validation, access controls, and monitoring, as well as perform regular security assessments and keep the system updated with the latest security patches. Additionally, using secure coding practices, security testing tools, and security best practices can help to prevent these vulnerabilities from occurring in the first place. Additionally, training employees and developers on security best practices is also important.

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