ISC BIND DoS Vulnerability (CVE-2021-25214) - Linux

# Copyright (C) 2021 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:/a:isc:bind";

if (description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.145863");
  script_version("2021-08-17T14:01:00+0000");
  script_tag(name:"last_modification", value:"2021-08-17 14:01:00 +0000 (Tue, 17 Aug 2021)");
  script_tag(name:"creation_date", value:"2021-04-30 03:09:26 +0000 (Fri, 30 Apr 2021)");
  script_tag(name:"cvss_base", value:"4.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:S/C:N/I:N/A:P");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2021-05-21 09:15:00 +0000 (Fri, 21 May 2021)");

  script_cve_id("CVE-2021-25214");

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

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

  script_name("ISC BIND DoS Vulnerability (CVE-2021-25214) - Linux");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2021 Greenbone Networks GmbH");
  script_family("Denial of Service");
  script_dependencies("gb_isc_bind_consolidation.nasl", "os_detection.nasl");
  script_mandatory_keys("isc/bind/detected", "Host/runs_unixoide");

  script_tag(name:"summary", value:"ISC BIND 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:"Incremental zone transfers (IXFR) provide a way of transferring
  changed portion(s) of a zone between servers. An IXFR stream containing SOA records with an owner
  name other than the transferred zone's apex may cause the receiving named server to inadvertently
  remove the SOA record for the zone in question from the zone database. This leads to an assertion
  failure when the next SOA refresh query for that zone is made.");

  script_tag(name:"impact", value:"When a vulnerable version of named receives a malformed IXFR
  triggering the flaw described above, the named process will terminate due to a failed assertion
  the next time the transferred secondary zone is refreshed.");

  script_tag(name:"affected", value:"BIND 9.8.5 through 9.8.8, 9.9.3 through 9.11.29, 9.12.0 through
  9.16.13, 9.9.3-S1 through 9.11.29-S1, 9.16.8-S1 through 9.16.13-S1 and 9.17.0 through 9.17.11.");

  script_tag(name:"solution", value:"Update to version 9.11.31, 9.16.15, 9.17.12, 9.11.31-S1,
  9.16.15-S1 or later.");

  script_xref(name:"URL", value:"https://kb.isc.org/docs/cve-2021-25214");

  exit(0);
}

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

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

if (!infos = get_app_full(cpe: CPE, port: port, exit_no_version: TRUE))
  exit(0);

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

if (version =~ "^9\.[0-9]+\.[0-9]+s[0-9]") {
  if (version_in_range(version: version, test_version: "9.9.3s1", test_version2: "9.11.29s1")) {
    report = report_fixed_ver(installed_version: version, fixed_version: "9.11.31-S1", install_path: location);
    security_message(port: port, data: report, proto: proto);
    exit(0);
  }

  if (version_in_range(version: version, test_version: "9.16.8s1", test_version2: "9.16.13s1")) {
    report = report_fixed_ver(installed_version: version, fixed_version: "9.16.15-S1", install_path: location);
    security_message(port: port, data: report, proto: proto);
    exit(0);
  }
} else {
  if (version_in_range(version: version, test_version: "9.8.5", test_version2: "9.8.8") ||
      version_in_range(version: version, test_version: "9.9.3", test_version2: "9.11.29")) {
    report = report_fixed_ver(installed_version: version, fixed_version: "9.11.31", install_path: location);
    security_message(port: port, data: report, proto: proto);
    exit(0);
  }

  if (version_in_range(version: version, test_version: "9.12.0", test_version2: "9.16.13")) {
    report = report_fixed_ver(installed_version: version, fixed_version: "9.16.15", install_path: location);
    security_message(port: port, data: report, proto: proto);
    exit(0);
  }

  if (version_in_range(version: version, test_version: "9.17.0", test_version2: "9.17.11")) {
    report = report_fixed_ver(installed_version: version, fixed_version: "9.17.12", install_path: location);
    security_message(port: port, data: report, proto: proto);
    exit(0);
  }
}

exit(99);