引言
SQL注入是一种常见的网络攻击手段，攻击者通过在输入字段中插入恶意的SQL代码，从而实现对数据库的非法访问或破坏。本文将深入探讨显错注入与盲注的攻防奥秘，帮助读者了解这两种攻击方式的特点、原理以及防御措施。
显错注入
定义
显错注入是指攻击者通过在目标系统中注入SQL代码，导致数据库错误信息直接显示在用户界面上，从而获取数据库结构、数据等信息。
攻击原理
- 错误处理机制：大多数数据库系统在执行错误的SQL语句时，会返回错误信息。攻击者利用这一机制，通过构造特定的SQL语句，使得错误信息被返回到用户界面。
- SQL语句构造：攻击者构造的SQL语句通常包含
AND、OR、LIKE等逻辑运算符，以及'、"等特殊字符，以达到欺骗数据库执行恶意代码的目的。
攻击示例
”`sql SELECT * FROM users WHERE username=‘admin’ AND ‘1’=‘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, 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