Unbound DNS Resolver < 1.6.8 DoS Vulnerability

# SPDX-FileCopyrightText: 2018 Greenbone AG
# 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-only

CPE = "cpe:/a:unbound:unbound";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.113091");
  script_version("2025-10-31T05:40:56+0000");
  script_tag(name:"last_modification", value:"2025-10-31 05:40:56 +0000 (Fri, 31 Oct 2025)");
  script_tag(name:"creation_date", value:"2018-01-24 15:09:10 +0100 (Wed, 24 Jan 2018)");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:P/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-10-09 23:24:00 +0000 (Wed, 09 Oct 2019)");

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

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

  script_cve_id("CVE-2017-15105");

  script_name("Unbound DNS Resolver < 1.6.8 DoS Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2018 Greenbone AG");
  script_family("Denial of Service");
  script_dependencies("gb_unbound_dns_detect.nasl");
  script_mandatory_keys("unbound/detected");

  script_tag(name:"summary", value:"Unbound DNS Resolver is prone to a denial of service (DoS)
  vulnerability.");

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

  script_tag(name:"insight", value:"A flaw was found in the way unbound before 1.6.8 validated
  wildcard-synthesized NSEC records.");

  script_tag(name:"impact", value:"An improperly validated wildcard NSEC record could be used to
  prove the non-existence (NXDOMAIN answer) of an existing wildcard record, or trick unbound into
  accepting a NODATA proof.");

  script_tag(name:"affected", value:"Unbound DNS Resolver versions prior to 1.6.8.");

  script_tag(name:"solution", value:"Update to version 1.6.8 later.");

  script_xref(name:"URL", value:"https://unbound.net/downloads/CVE-2017-15105.txt");

  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if( ! port = get_app_port( cpe: CPE ) )
  exit( 0 );

if( ! infos = get_app_version_and_proto( cpe: CPE, port: port ) )
  exit( 0 );

version = infos["version"];
proto = infos["proto"];

if( version_is_less( version: version, test_version: "1.6.8" ) ) {
  report = report_fixed_ver( installed_version: version, fixed_version: "1.6.8" );
  security_message( data: report, port: port, proto: proto );
  exit( 0 );
}

exit( 99 );