Javascript Snippet #06
This challenge covers the review of a snippet of code written in JavaScript
The Code Review Snippet challenges provide a snippet of JavaScript code where you are tasked with identifying potential vulnerabilities. This particular code sets up an Express application with EJS templating. One of the primary issues in the code is the dynamic creation of templates using user-provided data (req.query.name), which can lead to code execution vulnerabilities. Specifically, an attacker can inject EJS syntax into the name query parameter to execute arbitrary code on the server. The video explains how this vulnerability works and emphasizes the importance of using placeholders in templates instead of dynamically creating them based on user input.
In the provided JavaScript code, the main vulnerability lies in line 12 where the template is dynamically created using req.query.name. This allows an attacker to exploit the template syntax to execute arbitrary code, potentially gaining control of the server. The correct approach is to use placeholders in the template and map these placeholders to actual values during rendering. This ensures that user-provided data is safely incorporated into the template without risking code execution.
The video further demonstrates how an attacker might exploit this vulnerability by injecting EJS syntax to run system commands. By understanding this, developers can better appreciate the risks of dynamic template creation and the importance of secure coding practices.