Generic format string

###############################################################################
# OpenVAS Vulnerability Test
# $Id: misc_format_string.nasl 4750 2016-12-12 15:39:21Z cfi $
#
# Generic format string
#
# Authors:
# Michel Arboi <[email protected]>
#
# Copyright:
# Copyright (C) 2002 Michel Arboi
#
# 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.
###############################################################################

# References:
# Date:	 Wed, 20 Mar 2002 11:35:04 +0100 (CET)
# From:	"Wojciech Purczynski" <[email protected]>
# To: [email protected], [email protected]
# CC: [email protected]
# Subject: Bypassing libsafe format string protection
# 
# TBD: Add those tests:
#	printf("%'n", &target);
#	printf("%In", &target);
#	printf("%2$n", "unused argument", &target);

if(description)
{
  script_id(11133);
  script_version("$Revision: 4750 $");
  script_tag(name:"last_modification", value:"$Date: 2016-12-12 16:39:21 +0100 (Mon, 12 Dec 2016) $");
  script_tag(name:"creation_date", value:"2005-11-03 14:08:04 +0100 (Thu, 03 Nov 2005)");
  script_tag(name:"cvss_base", value:"7.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_name("Generic format string");
  script_category(ACT_DESTRUCTIVE_ATTACK);
  script_copyright("This script is Copyright (C) 2002 Michel Arboi");
  script_family("Gain a shell remotely");
  script_dependencies("find_service.nasl");
  script_require_ports("Services/unknown");

  script_xref(name:"URL", value:"http://www.securityfocus.com/archive/1/81565");

  tag_summary = "The remote service is vulnerable to a format string attack
  An attacker may use this flaw to execute arbitrary code on this host.";

  tag_solution = "Upgrade your software or contact your vendor and inform it of this
  vulnerability";

  script_tag(name:"solution", value:tag_solution);
  script_tag(name:"summary", value:tag_summary);

  script_tag(name:"qod_type", value:"remote_vul"); 

  exit(0);
}

include('misc_func.inc');

port = get_unknown_port( nodefault:TRUE );

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

send(socket: soc, data: "xxxxxxxxxxxxxxxxxxxxxxxxxx");
r1 = recv(socket: soc, length: 256, min:1);
close(soc);

flag = 1;
if (egrep(pattern:"[0-9a-fA-F]{4}", string: r1)) flag = 0;

soc = open_sock_tcp(port);
if (! soc) exit(0);
send(socket: soc, 
	data: crap(data:"%#0123456x%04x%x%s%p%n%d%o%u%c%h%l%q%j%z%Z%t%i%e%g%f%a%C%S%04x%%#0123456x%%x%%s%%p%%n%%d%%o%%u%%c%%h%%l%%q%%j%%z%%Z%%t%%i%%e%%g%%f%%a%%C%%S%%04x",
		length:256) );
r2 = recv(socket: soc, length: 256, min:1);
close(soc);


soc = open_sock_tcp(port);
if (! soc)
{
  security_message(port);
  exit(0);
}

close(soc);

if (flag && (egrep(pattern:"[0-9a-fA-F]{4}", string: r2)))
{
  security_message(port);
  exit(0);
}