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To advance our discussion on MySQL penetration testing and defenses, tell me:

User-Defined Functions (UDFs) allow developers to extend MySQL's functionality by loading compiled C/C++ code from external shared libraries ( .so on Linux, .dll on Windows). If an attacker has administrative database access and file-writing capabilities, UDF injection can yield Remote Code Execution (RCE) with the privileges of the MySQL service running daemon (often mysql or SYSTEM ). Compilation and Transfer

In older, unpatched systems running specific versions of MariaDB and MySQL (around versions 5.1 to 5.5), a critical flaw allows authentication bypass due to a bad cast in the checking function. If a user inputs a password, there is a 1-in-256 chance that the memeory comparison returns true regardless of accuracy. mysql hacktricks verified

| Attack Vector | Description | |---|---| | | Executes OS command, returns exit code | | sys_eval() | Executes OS command, returns output | | do_system() | Calls system() function | | shell_exec() | Alternative system command execution |

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If the MySQL server runs as root or SYSTEM on the operating system, and the database user has the FILE privilege, you can compile and inject a custom shared library ( .so on Linux, .dll on Windows) to execute arbitrary system commands. SHOW VARIABLES LIKE 'plugin_dir'; Use code with caution.

' AND (SELECT IF(SUBSTRING(user(),1,1)='r', SLEEP(5), 0))-- - To advance our discussion on MySQL penetration testing

Modern MySQL installations utilize the secure_file_priv variable to restrict file operations to a designated directory or disable them entirely. Check this variable before proceeding: SHOW VARIABLES LIKE "secure_file_priv"; Use code with caution.