PowerDNS Recursor < 4.1.18, 4.2.0 < 4.2.4, 4.3.0 < 4.3.4 DoS Vulnerability

# SPDX-FileCopyrightText: 2020 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:powerdns:recursor";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.144824");
  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:"2020-10-26 06:05:46 +0000 (Mon, 26 Oct 2020)");
  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_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-12-23 22:15:00 +0000 (Wed, 23 Dec 2020)");

  script_cve_id("CVE-2020-25829");

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

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

  script_name("PowerDNS Recursor < 4.1.18, 4.2.0 < 4.2.4, 4.3.0 < 4.3.4 DoS Vulnerability");

  script_category(ACT_GATHER_INFO);

  script_copyright("Copyright (C) 2020 Greenbone AG");
  script_family("Denial of Service");
  script_dependencies("gb_powerdns_dns_detect.nasl");
  script_mandatory_keys("powerdns/recursor/detected");

  script_tag(name:"summary", value:"PowerDNS Recursor is prone to a denial of service vulnerability.");

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

  script_tag(name:"insight", value:"An issue has been found in PowerDNS Recursor where a remote attacker can cause
  the cached records for a given name to be updated to the 'Bogus' DNSSEC validation state, instead of their
  actual DNSSEC 'Secure' state, via a DNS ANY query. This results in a denial of service for installations that
  always validate (dnssec=validate) and for clients requesting validation when on-demand validation is enabled
  (dnssec=process).");

  script_tag(name:"affected", value:"PowerDNS Recursor version 4.1.17 and prior, 4.2.0 through 4.2.4
  and 4.3.0 through 4.3.4.");

  script_tag(name:"solution", value:"Update to version 4.1.18, 4.2.5, 4.3.5 or later.");

  script_xref(name:"URL", value:"https://docs.powerdns.com/recursor/security-advisories/powerdns-advisory-2020-07.html");

  exit(0);
}

include("version_func.inc");
include("host_details.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: "4.1.8")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "4.1.18");
  security_message(data: report, port: port, proto: proto);
  exit(0);
}

if (version_in_range(version: version, test_version: "4.2.0", test_version2: "4.2.4")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "4.2.5");
  security_message(data: report, port: port, proto: proto);
  exit(0);
}

if (version_in_range(version: version, test_version: "4.3.0", test_version2: "4.3.4")) {
  report = report_fixed_ver(installed_version: version, fixed_version: "4.3.5");
  security_message(data: report, port: port, proto: proto);
  exit(0);
}

exit(99);