# Usage of externally controlled input to select code

## Overview

* **Rule ID**: `javascript_lang_import_using_user_input`
* **Applicable Languages**: Javascript
* **Weakness ID**: CWE-470

## Description

Loading code dynamically based on a path specified by user input can enable attackers to run arbitrary code on your system.

## Remediation Guidelines

* **Do not pass user or request input directly to the `require()` function.** This can introduce significant security vulnerabilities.
* **Sanitize user input if it is necessary to dynamically load code.** Ensure that the input is thoroughly checked and cleaned to avoid processing malicious data.
* **Adopt a safelist approach when dynamically loading code based on user input.** Confirm that the input matches a predefined list of safe values before proceeding.

  ```java
  var path = req.body.path;
  if (['users', 'posts', 'pages'].includes(path)) {
    require(`${path}.js`);
  }

  ```

## References

* [**CWE-470: Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')**](https://cwe.mitre.org/data/definitions/470.html)
* [**OWASP Top 10: A03:2021 - Injection**](https://owasp.org/Top10/A03_2021-Injection/)

## Configuration

To omit this rule during a scan, and to provide you with continuous 24/7 code-level scanning, you can employ our [**SAST TOOL**](https://scopy.sec1.io/login)


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# Agent Instructions: Querying This Documentation

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Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
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```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.