命令注入是一种常见的网络安全漏洞，它允许攻击者通过在应用程序中注入恶意命令来执行非授权的操作。在DVWA（Damn Vulnerable Web Application）这样的安全测试环境中，命令注入是一个重要的学习对象。本文将深入探讨DVWA中的命令注入问题，并详细说明如何解决无法浏览用户数据的难题。
命令注入概述
命令注入是指攻击者通过在输入字段中插入恶意代码，使得应用程序执行非预期的命令。这种漏洞通常出现在动态SQL查询、外部程序调用或者命令行工具的调用中。在Web应用程序中，命令注入可能导致数据泄露、服务器被控制、恶意软件传播等严重后果。
DVWA命令注入案例
在DVWA中，我们可以通过访问“SQL注入”模块来观察命令注入的一个典型例子。在这个模块中，攻击者可以通过修改URL参数来注入SQL命令。
1. 漏洞演示
假设我们访问以下链接：
”` http://dvwa.com/vulnerabilities/sqli/?id=1’ UNION SELECT null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, null, 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