Course

This course delves into a specific vulnerability in ExpressJS, stemming from the improper use of the `render` method on user-supplied data. The course outlines the problem and demonstrates how an attacker can exploit this flaw to perform local file read (LFR) attacks. By following the provided code snippets and examples, you will understand how the misuse of the `render` function can lead to severe security issues.

The video transcript further elucidates the practical steps of exploiting this vulnerability. You will see how to manipulate the parameters to read sensitive files from the server. The course concludes with a reminder to always validate the format of parameters in web applications to prevent such vulnerabilities.