How to conduct a website security audit: Advanced methodologies and techniques

Ensuring the security of a website is fundamental for preventing cyberattacks and protecting user data. A comprehensive security audit identifies potential vulnerabilities before they can be exploited by external or internal attackers. Check out this article on security best practices and the importance of regular audits to strengthen your website's security.

Audit Methodologies: Black Box, Gray Box, and White Box Approaches

1. Black Box Testing

Black box tests simulate external attacks, with no prior knowledge of the site or internal configurations. This approach tests the site’s resilience against typical hacker attacks from the outside.

Practical Process for Black Box Audit

1. Network Infrastructure Scanning: This step identifies open services accessible externally, including a network port scan to reveal exposed services that may serve as entry points.
2. Identifying External Weaknesses: If critical services are detected, it's essential to validate if their versions are vulnerable or outdated. In-depth searches in vulnerability databases, such as Mitre CVE, provide details on specific exploitable flaws.

2. Gray Box Testing

Gray box testing combines external knowledge with some technical insights (like technology versions or modules used), though without full access to source code or internal configurations. This semi-internal approach verifies the site's robustness in semi-open scenarios.

Gray Box Identification Techniques

1. Detecting Technologies and Versions: Reconnaissance helps identify frameworks, CMSs, and libraries in use, which allows for checking version-specific vulnerabilities.
2. Searching for Exploitable Vulnerabilities: Resources such as HackTricks (link) catalog specific techniques for exploiting particular technologies or versions. This site provides concrete guides for testing intrusions on particular technologies, including specific configurations or common vulnerabilities.

3. White Box Testing: Source Code Security Analysis

In the white box approach, access to source code allows for direct checks on code quality and security. This includes a thorough review of coding practices, authentication mechanisms, and user input handling.

Process for Auditing Source Code in White Box

1. Validation of Injectable Parameters Security: User input fields must be thoroughly processed to prevent SQL injection, XSS, or other code injection attacks. This involves strict controls on user inputs and the handling of user data.
2. Session and Authentication Management Analysis: Confirm that the site uses secure sessions and robust authentication. Passwords and other sensitive information should never be stored in plain text and should be securely hashed.
3. Auditing Critical Functions: All sensitive functions (like access to sensitive data or admin privileges) must be tightly secured, with restricted access and activity logs to track suspicious activities.

Detailed Steps for a Comprehensive Security Audit

1. Reconnaissance and Information Gathering

The reconnaissance phase provides a better understanding of the infrastructure, identifying the technologies and configurations in place.

1. HTTP Headers and Server Responses Analysis: This helps detect specific technologies, their versions, and sometimes even default configuration details.
2. Exposed Endpoint Inspection: Identifying unsecured APIs or endpoints can reveal vulnerable areas. This step also verifies if sensitive information is disclosed.

2. Identifying and Exploiting Potential Vulnerabilities

Vulnerabilities identified during reconnaissance must be verified and tested to determine if they are actually exploitable.

1. Analysis of Software Version Vulnerabilities: Outdated or vulnerable technologies should be cataloged and tested in a controlled environment. If the site uses an older version of PHP or a database, known vulnerabilities in these versions can be exploited in test conditions.
2. Exploitation in a Secure Environment: Where possible, conduct exploit tests in a sandbox environment to understand the real risk without impacting the live site.

3. Fuzzing for Injectable Parameters

Fuzzing involves injecting random inputs into fields to identify abnormal behaviors and potential vulnerabilities.

How to Perform Advanced Fuzzing?

1. Identifying Injection Points: Detect each user input field, URL parameter, and text area that could potentially be exploited.
2. Using Fuzzing Tools with Varied Values: By sending unexpected or incorrect data, you can test how the site handles these inputs. This is crucial for detecting flaws such as SQL injection or Cross-Site Scripting (XSS).

4. Privilege Escalation: Validating Permissions Protection

Once access to the site is obtained (even limited), the final objective is to test permission security and verify if an attacker can gain higher privileges.

Process for Testing Privilege Escalation

1. Identifying Initial Privileges: List the access rights and restrictions applicable to the account or access obtained.
2. Attempting to Gain Higher Privileges: If flaws allow role modifications or admin access, this is a critical security flaw that must be corrected to prevent breaches.

Conclusion

A complete security audit, integrating black box, gray box, and white box approaches, helps identify a broad spectrum of potential vulnerabilities. By applying advanced techniques like analysis, fuzzing, and privilege escalation, you optimize your website’s security, protect users, and reduce the risk of cyberattacks.