Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : NSD vulnerabilities (USN-8474-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8474-1. 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(322955);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/06/26");

  script_cve_id(
    "CVE-2026-12244",
    "CVE-2026-12245",
    "CVE-2026-12246",
    "CVE-2026-12490"
  );
  script_xref(name:"USN", value:"8474-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : NSD vulnerabilities (USN-8474-1)");

  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 / 26.04 LTS host has packages installed that
are affected by multiple vulnerabilities as referenced in the USN-8474-1 advisory.

    It was discovered that NSD incorrectly handled APL resource records with an address length larger than
    permitted for the address family. A remote attacker could use this to cause a stack-based buffer overflow
    when the zone is written to disk, potentially executing arbitrary code with the privileges of the NSD
    server. (CVE-2026-12246)

    It was discovered that NSD incorrectly handled SVCB resource records. A remote attacker could use this to
    cause a heap overflow, potentially executing arbitrary code with the privileges of the NSD server. This
    issue only affected Ubuntu 26.04 LTS. (CVE-2026-12244)

    It was discovered that NSD had a use-after-free vulnerability in TLS connection error logging. A remote
    attacker could use this to cause a denial of service by crashing the server process. This issue only
    affected Ubuntu 26.04 LTS. (CVE-2026-12245)

    It was discovered that NSD incorrectly handled TLS authentication for zone transfers. An attacker could
    bypass transfer security restrictions when certain conditions were met. This issue only affected Ubuntu
    26.04 LTS. (CVE-2026-12490)

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-8474-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected nsd and / or nsd3 packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/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:L/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-12244");
  script_set_attribute(attribute:"cvss4_score_source", value:"CVE-2026-12245");

  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:"2026/06/25");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/06/25");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/06/26");

  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:26.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:nsd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:nsd3");
  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 || '26.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 18.04 / 20.04 / 22.04 / 24.04 / 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': 'nsd', 'pkgver': '4.1.7-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '16.04', 'pkgname': 'nsd3', 'pkgver': '4.1.7-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '18.04', 'pkgname': 'nsd', 'pkgver': '4.1.17-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '20.04', 'pkgname': 'nsd', 'pkgver': '4.1.26-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '22.04', 'pkgname': 'nsd', 'pkgver': '4.3.9-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '24.04', 'pkgname': 'nsd', 'pkgver': '4.8.0-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12246']},
    {'osver': '26.04', 'pkgname': 'nsd', 'pkgver': '4.14.0-1ubuntu0.1~esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2026-12244', 'CVE-2026-12245', 'CVE-2026-12246', 'CVE-2026-12490']}
];

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, 'nsd / nsd3');
}