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# Unsanitized User Input in OS Command

## Overview

* **Rule ID**: `java_lang_os_command_injection`
* **Applicable Languages**: Java
* **Weakness ID**: CWE-78

## Description

Directly including external or user-defined input in an OS command exposes the system to potential command injection attacks. This vulnerability allows attackers to execute unauthorized commands on the operating system, potentially compromising system integrity.

## Remediation Guidelines

* **Avoid** using OS commands that incorporate dynamic input directly. Instead, consider safer alternatives such as libraries or built-in functions that achieve the same objective without executing system commands.
* **Use** hardcoded values for any input included in OS commands. This approach minimizes risk by ensuring only predefined inputs are used, preventing attackers from injecting malicious commands.

  ```java
  String filePattern = "*.json";
  if ("xml".equals(request.getParameter("format"))) {
  filePattern = "*.xml";
  }

  Process process = Runtime.getRuntime().exec("ls /myDir/" + filePattern);
  ```

## References

* [**OWASP command injection explained**](https://owasp.org/www-community/attacks/Command_Injection)
* [**CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')**](https://cwe.mitre.org/data/definitions/78.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)