Ubuntu 20.04 LTS / 22.04 LTS / 23.10 : Dnsmasq vulnerabilities (USN-6657-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6657-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('compat.inc');

if (description)
{
  script_id(191021);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/28");

  script_cve_id("CVE-2023-28450", "CVE-2023-50387", "CVE-2023-50868");
  script_xref(name:"USN", value:"6657-1");

  script_name(english:"Ubuntu 20.04 LTS / 22.04 LTS / 23.10 : Dnsmasq vulnerabilities (USN-6657-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 20.04 LTS / 22.04 LTS / 23.10 host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-6657-1 advisory.

    Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner discovered that Dnsmasq icorrectly
    handled validating DNSSEC messages. A remote attacker could possibly use this issue to cause Dnsmasq to
    consume resources, leading to a denial of service. (CVE-2023-50387)

    It was discovered that Dnsmasq incorrectly handled preparing an NSEC3 closest encloser proof. A remote
    attacker could possibly use this issue to cause Dnsmasq to consume resources, leading to a denial of
    service. (CVE-2023-50868)

    It was discovered that Dnsmasq incorrectly set the maximum EDNS.0 UDP packet size as required by DNS Flag
    Day 2020. This issue only affected Ubuntu 23.10. (CVE-2023-28450)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-6657-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-50387");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/03/15");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/02/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/02/26");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:22.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:23.10");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dnsmasq");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dnsmasq-base");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dnsmasq-base-lua");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:dnsmasq-utils");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Ubuntu Local Security Checks");

  script_copyright(english:"Ubuntu Security Notice (C) 2024 Canonical, Inc. / NASL script (C) 2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('20.04' >< os_release || '22.04' >< os_release || '23.10' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 20.04 / 22.04 / 23.10', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '20.04', 'pkgname': 'dnsmasq', 'pkgver': '2.90-0ubuntu0.20.04.1'},
    {'osver': '20.04', 'pkgname': 'dnsmasq-base', 'pkgver': '2.90-0ubuntu0.20.04.1'},
    {'osver': '20.04', 'pkgname': 'dnsmasq-base-lua', 'pkgver': '2.90-0ubuntu0.20.04.1'},
    {'osver': '20.04', 'pkgname': 'dnsmasq-utils', 'pkgver': '2.90-0ubuntu0.20.04.1'},
    {'osver': '22.04', 'pkgname': 'dnsmasq', 'pkgver': '2.90-0ubuntu0.22.04.1'},
    {'osver': '22.04', 'pkgname': 'dnsmasq-base', 'pkgver': '2.90-0ubuntu0.22.04.1'},
    {'osver': '22.04', 'pkgname': 'dnsmasq-base-lua', 'pkgver': '2.90-0ubuntu0.22.04.1'},
    {'osver': '22.04', 'pkgname': 'dnsmasq-utils', 'pkgver': '2.90-0ubuntu0.22.04.1'},
    {'osver': '23.10', 'pkgname': 'dnsmasq', 'pkgver': '2.90-0ubuntu0.23.10.1'},
    {'osver': '23.10', 'pkgname': 'dnsmasq-base', 'pkgver': '2.90-0ubuntu0.23.10.1'},
    {'osver': '23.10', 'pkgname': 'dnsmasq-base-lua', 'pkgver': '2.90-0ubuntu0.23.10.1'},
    {'osver': '23.10', 'pkgname': 'dnsmasq-utils', 'pkgver': '2.90-0ubuntu0.23.10.1'}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  var extra = '';
  extra += ubuntu_report_get();
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'dnsmasq / dnsmasq-base / dnsmasq-base-lua / dnsmasq-utils');
}