OWASP TOP 10: File upload vulnerabilities ~2023

Uploading malicious files can make the website vulnerable to client-side attacks such as XSS or Cross-site Content Hijacking. Uploaded files might trigger vulnerabilities in broken libraries/applications on the client side

The OWASP Top 10 provides rankings of—and remediation guidance for—the top 10 most critical web application security risks. Leveraging the extensive knowledge and experience of the OWASP's open community contributors, the report is based on a consensus among security experts from around the world.

What is File upload vulnerabilities?

File upload vulnerabilities are when a web server allows users to upload files to its filesystem without sufficiently validating things like their name, type, contents, or size.

File upload vulnerabilities are a serious issue that can allow attackers to upload malicious code or files to a web application, potentially giving them access to sensitive information or allowing them to take control of the system. A comprehensive course on file upload vulnerabilities would cover the following topics:

1. Introduction to file upload vulnerabilities: Explanation of what file upload vulnerabilities are, how they can be exploited, and the potential impact of an attack.

2. Types of file upload vulnerabilities: Overview of the different types of file upload vulnerabilities, including direct object reference, insufficient file type validation, unrestricted file upload, and others.

3. Prevention and mitigation techniques: Discussion of the best practices for preventing and mitigating file upload vulnerabilities, including file type validation, file size restrictions, file name restrictions, and other security measures.

4. Exploitation of file upload vulnerabilities: Explanation of how attackers can exploit file upload vulnerabilities to gain access to sensitive data, install malware, or take control of the system.

5. Detection and testing: Overview of the methods used to detect and test for file upload vulnerabilities, including manual testing, automated tools, and other techniques.

6. Case studies and real-world examples: Discussion of real-world examples of file upload vulnerabilities, including lessons learned and best practices.

7. Secure coding practices: Overview of the secure coding practices that can help prevent file upload vulnerabilities, including input validation, output encoding, and other security measures.

8. Compliance and audits: Explanation of the various regulations, standards, and best practices related to file upload vulnerabilities and how they are audited and enforced.

9. Patching and remediation: Explanation of how file upload vulnerabilities can be patched and remediated, including methods for fixing the underlying code or applying security updates.

10. Hands-on experience: Practical exercises that allow students to gain hands-on experience in identifying, testing, and remediating file upload vulnerabilities.

This course would be suitable for developers, security professionals, and anyone interested in improving their understanding of file upload vulnerabilities and how to prevent them. By the end of the course, students will be equipped with the knowledge and skills to identify, test for, and remediate file upload vulnerabilities in web applications, helping to protect against malicious attacks and safeguard sensitive data.