Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Net::CIDR::Lite vulnerabilities (USN-8406-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8406-1. 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(320398);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/11");

  script_cve_id("CVE-2021-47154", "CVE-2026-40198", "CVE-2026-40199");
  script_xref(name:"USN", value:"8406-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS : Net::CIDR::Lite vulnerabilities (USN-8406-1)");

  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 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 25.10 / 26.04 LTS host has a package
installed that is affected by multiple vulnerabilities as referenced in the USN-8406-1 advisory.

    Dave Rolsky discovered that Net::CIDR::Lite did not properly handle extraneous zero characters at the
    beginning of an IP address string. A remote attacker could possibly use this issue to bypass access
    controls that are based on IP addresses. This issue only affected Ubuntu 16.04 LTS and Ubuntu 18.04 LTS.
    (CVE-2021-47154)

    It was discovered that Net::CIDR::Lite did not properly validate the IPv6 group count when handling
    uncompressed IPv6 addresses. A remote attacker could possibly use this issue to bypass access controls.
    (CVE-2026-40198)

    It was discovered that Net::CIDR::Lite mishandled IPv4 mapped IPv6 addresses. A remote attacker could
    possibly use this issue to bypass access controls that are based on IP addresses. (CVE-2026-40199)

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-8406-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libnet-cidr-lite-perl package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:C/A:N");
  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:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-40198");

  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:"2024/03/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  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:24.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:25.10");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnet-cidr-lite-perl");
  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) 2026 Canonical, Inc. / NASL script (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.nasl", "ubuntu_pro_sub_detect.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 (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release || '22.04' >< os_release || '24.04' >< os_release || '25.10' >< os_release || '26.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 25.10 / 26.04', '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 ubuntu_pro_detected = get_kb_item('Host/Ubuntu/Pro/Services/esm-apps');
ubuntu_pro_detected = !empty_or_null(ubuntu_pro_detected);

var pro_caveat_needed = FALSE;

var pkgs = [
    {'osver': '16.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.21-1ubuntu0.16.04.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-47154', 'CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '18.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.21-1ubuntu0.18.04.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-47154', 'CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '20.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.21-2ubuntu0.1+esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '22.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.22-1ubuntu0.1', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '24.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.22-2ubuntu0.24.04.1', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '25.10', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.22-2ubuntu0.25.10.1', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-40198', 'CVE-2026-40199']},
    {'osver': '26.04', 'pkgname': 'libnet-cidr-lite-perl', 'pkgver': '0.22-2ubuntu0.26.04.1', 'ubuntu_pro': FALSE, 'cves': ['CVE-2026-40198', 'CVE-2026-40199']}
];

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 (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  var pro_required = NULL;
  if (!empty_or_null(package_array['ubuntu_pro'])) pro_required = package_array['ubuntu_pro'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) {
        flag++;
        if (!ubuntu_pro_detected && !pro_caveat_needed) pro_caveat_needed = pro_required;
    }
  }
}

if (flag)
{
  var extra = '';
  if (pro_caveat_needed) {
    extra += 'NOTE: This vulnerability check contains fixes that apply to packages only \n';
    extra += 'available in Ubuntu ESM repositories. Access to these package security updates \n';
    extra += 'require an Ubuntu Pro subscription.\n\n';
  }
  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, 'libnet-cidr-lite-perl');
}