Cisco NX-OS Border Gateway Protocol Component DoS Vulnerability

# Copyright (C) 2013 Greenbone Networks GmbH
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# 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.

CPE = "cpe:/o:cisco:nx-os";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.103815");
  script_version("2022-12-26T10:12:01+0000");
  script_tag(name:"last_modification", value:"2022-12-26 10:12:01 +0000 (Mon, 26 Dec 2022)");
  script_tag(name:"creation_date", value:"2013-10-18 10:24:45 +0200 (Fri, 18 Oct 2013)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");

  script_cve_id("CVE-2012-4098");

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

  script_tag(name:"solution_type", value:"VendorFix");

  script_name("Cisco NX-OS Border Gateway Protocol Component DoS Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2013 Greenbone Networks GmbH");
  script_family("CISCO");
  script_dependencies("gb_cisco_nx_os_consolidation.nasl");
  script_mandatory_keys("cisco/nx_os/detected", "cisco/nx_os/device", "cisco/nx_os/model");

  script_tag(name:"summary", value:"A vulnerability in the Border Gateway Protocol (BGP) component
  of Cisco NX-OS Software could allow an unauthenticated, remote attacker to create a denial of
  service (DoS) condition by causing the BGP service to reset and resync.");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");

  script_tag(name:"insight", value:"The vulnerability is due to improper filtering of invalid AS
  Path values. An attacker could exploit this vulnerability by sending a malformed BGP update to a
  downstream peer of the affected device.");

  script_tag(name:"impact", value:"A successful exploit could result in the downstream peers
  resetting the BGP connection with the affected device.");

  script_tag(name:"solution", value:"See the referenced vendor advisory for a solution.");

  script_tag(name:"affected", value:"Cisco Nexus 7000 Series running on NX-OS.");

  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/62858");
  script_xref(name:"URL", value:"https://tools.cisco.com/security/center/content/CiscoSecurityNotice/CVE-2012-4098");

  exit(0);
}

include("host_details.inc");
include("revisions-lib.inc");
include("version_func.inc");

if( ! device = get_kb_item( "cisco/nx_os/device" ) )
  exit( 0 );

if( device != "Nexus" )
  exit( 0 );

if( ! nx_model = get_kb_item( "cisco/nx_os/model" ) )
  exit( 0 );

if( nx_model !~ "^C?7" )
  exit( 0 );

if( ! version = get_app_version( cpe:CPE, nofork:TRUE ) )
  exit( 0 );

first_found = "5.2.0.180.S14";
fixed       = "5.2.0.218.S0";

vers = ereg_replace( pattern:'[()]', replace:".", string:version );
vers = ereg_replace( pattern:'\\.$', replace:"", string:vers );

if( revcomp( a:vers, b:first_found ) >= 0 && revcomp( a:vers, b:fixed ) <= 0 ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"5.2(0.218)S0" );
  security_message( port:0, data:report );
  exit( 0 );
}

exit( 99 );