Advanced Techniques of using udf for privilege escalation in mysql

For cant open shared library udf. dll I believe that many friends who use mysql to raise permissions should not be unfamiliar with it. It is clearly a root user but they are using udf. this error is prompted when a user-defined function is created by dll Elevation of Privilege. In the past, this situation was generally abandoned.

 
After testing, we found that the app server can use udf. dll to escalate permissions by 5.037 when setting up a php environment.
 
The php environment built by apache + php + mysql + phpmyadmin cannot use 5.1
 
Why can't one of the two systems be used? The reason is very simple because udf must be started in version 5.1. the dll file can be placed in the lib/blugin file under the mysql installation directory to create user-defined functions, and this directory does not exist by default, and mysql into dumpfile cannot create folders when exporting files, in mysql 5.1, udf was started. the user-defined functions cannot be created when the dll is imported to the system directory. when the dll is imported to the system directory, you cannot create user-defined functions. The mysql version in the system that can be elevation of permission is 5.0.37, And the mysql version in the system that cannot be elevation of permission is 5.1, exactly in line with the above statement.
 
Execute create function mycmd return string soname udf in an unusable System (5.037. the prompt cant open shared library udf is displayed during dll. the dll error message indicates that a user-defined function cannot be created in the exported system directory. dll is imported to the lib/blugin directory under the mysql installation directory. I already know that the mysql installation directory is: "c: program filesmysqlmysql server 5.1 "there is currently no lin/plugin directory under this directory. We use webshell to create the lib folder under the mysql installation directory, and then create the plugin folder in the lib folder in udf. in php, write "c: program filesmysqlmysql server 5.1libpluginudf.dll" as the dll export path ". In this case, you can execute the SQL command such as select mycmd ("net user"); to execute it intelligently...
 
Create the lib/plugin directory under the mysql installation directory, and then set the udf. the dll file is exported to this directory, which resolves "cant open shared library udf" in mysql 5.1 and later versions. dll "error ....