Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Unbound vulnerabilities (USN-8946-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-8946-1. 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(370514);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id(
    "CVE-2023-50387",
    "CVE-2023-50868",
    "CVE-2026-32665",
    "CVE-2026-40691",
    "CVE-2026-44690",
    "CVE-2026-50252",
    "CVE-2026-55973",
    "CVE-2026-80225",
    "CVE-2026-81634",
    "CVE-2026-85501"
  );
  script_xref(name:"IAVA", value:"2026-A-1070-S");
  script_xref(name:"USN", value:"8946-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : Unbound vulnerabilities (USN-8946-1)");

  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 14.04 LTS / 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-8946-1 advisory.

    It was discovered that Unbound incorrectly handled certain TCP connections. A remote attacker could
    possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This issue
    only affected Ubuntu 26.04 LTS, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-80225)

    It was discovered that Unbound incorrectly handled certain DNS responses. A remote attacker could possibly
    use this issue to crash Unbound, resulting in a denial of service. (CVE-2026-81634)

    It was discovered that Unbound incorrectly handled certain DNS responses during DNSSEC validation. A
    remote attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial
    of service. (CVE-2026-85501)

    It was discovered that Unbound incorrectly handled outgoing network ports. A remote attacker could
    possibly use this issue to crash Unbound, resulting in a denial of service. (CVE-2026-50252)

    It was discovered that Unbound incorrectly handled certain DNSCrypt packets. A remote attacker could
    possibly use this issue to crash Unbound, resulting in a denial of service. This issue only affected
    Ubuntu 26.04 LTS, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS and Ubuntu 18.04 LTS.
    (CVE-2026-40691)

    It was discovered that Unbound incorrectly handled certain cached DNS responses. A remote attacker could
    possibly use this issue to poison Unbound's cache. This issue only affected Ubuntu 26.04 LTS, Ubuntu 24.04
    LTS, Ubuntu 22.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-44690)

    It was discovered that Unbound incorrectly handled certain DNS-over-QUIC connections. A remote attacker
    could possibly use this issue to cause Unbound to consume resources, leading to a denial of service. This
    issue only affected Ubuntu 26.04 LTS. (CVE-2026-32665)

    It was discovered that Unbound incorrectly handled certain EDNS options. A remote attacker could possibly
    use this issue to crash Unbound, resulting in a denial of service. This issue only affected Ubuntu 26.04
    LTS. (CVE-2026-55973)

    Elias Heftrig, Haya Schulmann, Niklas Vogel, and Michael Waidner discovered that Unbound incorrectly
    handled validating DNSSEC messages. A remote attacker could possibly use this issue to cause Unbound to
    consume resources, leading to a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 16.04
    LTS and Ubuntu 14.04 LTS. (CVE-2023-50387)

    It was discovered that Unbound incorrectly handled preparing an NSEC3 closest encloser proof. A remote
    attacker could possibly use this issue to cause Unbound to consume resources, leading to a denial of
    service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 16.04 LTS and Ubuntu 14.04 LTS.
    (CVE-2023-50868)

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-8946-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:N/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss4_vector", value:"CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:H");
  script_set_attribute(attribute:"cvss4_supplemental", value:"CVSS:4.0/U:Amber");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:P");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-50252");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2021/08/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04:-:lts");
  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:libunbound2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libunbound8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-unbound");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python3-unbound");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:unbound");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:unbound-anchor");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:unbound-host");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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_info2.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 (! ('14.04' >< os_release || '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 14.04 / 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 pkgs = [
    {'osver': '14.04', 'pkgname': 'libunbound2', 'pkgver': '1.4.22-1ubuntu4.14.04.3+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '14.04', 'pkgname': 'python-unbound', 'pkgver': '1.4.22-1ubuntu4.14.04.3+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '14.04', 'pkgname': 'unbound', 'pkgver': '1.4.22-1ubuntu4.14.04.3+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '14.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.4.22-1ubuntu4.14.04.3+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '14.04', 'pkgname': 'unbound-host', 'pkgver': '1.4.22-1ubuntu4.14.04.3+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '16.04', 'pkgname': 'libunbound2', 'pkgver': '1.5.8-1ubuntu1.1+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '16.04', 'pkgname': 'python-unbound', 'pkgver': '1.5.8-1ubuntu1.1+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '16.04', 'pkgname': 'unbound', 'pkgver': '1.5.8-1ubuntu1.1+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '16.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.5.8-1ubuntu1.1+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '16.04', 'pkgname': 'unbound-host', 'pkgver': '1.5.8-1ubuntu1.1+esm5', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'libunbound2', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'python-unbound', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'python3-unbound', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'unbound', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '18.04', 'pkgname': 'unbound-host', 'pkgver': '1.6.7-1ubuntu2.6+esm6', 'cves': ['CVE-2023-50387', 'CVE-2023-50868', 'CVE-2026-40691', 'CVE-2026-50252', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'libunbound8', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'python-unbound', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'python3-unbound', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'unbound', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '20.04', 'pkgname': 'unbound-host', 'pkgver': '1.9.4-2ubuntu1.11+esm3', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '22.04', 'pkgname': 'libunbound8', 'pkgver': '1.13.1-1ubuntu5.17', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '22.04', 'pkgname': 'python3-unbound', 'pkgver': '1.13.1-1ubuntu5.17', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '22.04', 'pkgname': 'unbound', 'pkgver': '1.13.1-1ubuntu5.17', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '22.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.13.1-1ubuntu5.17', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '22.04', 'pkgname': 'unbound-host', 'pkgver': '1.13.1-1ubuntu5.17', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '24.04', 'pkgname': 'libunbound8', 'pkgver': '1.19.2-1ubuntu3.12', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '24.04', 'pkgname': 'python3-unbound', 'pkgver': '1.19.2-1ubuntu3.12', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '24.04', 'pkgname': 'unbound', 'pkgver': '1.19.2-1ubuntu3.12', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '24.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.19.2-1ubuntu3.12', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '24.04', 'pkgname': 'unbound-host', 'pkgver': '1.19.2-1ubuntu3.12', 'cves': ['CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '26.04', 'pkgname': 'libunbound8', 'pkgver': '1.24.2-1ubuntu2.4', 'cves': ['CVE-2026-32665', 'CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-55973', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '26.04', 'pkgname': 'python3-unbound', 'pkgver': '1.24.2-1ubuntu2.4', 'cves': ['CVE-2026-32665', 'CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-55973', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '26.04', 'pkgname': 'unbound', 'pkgver': '1.24.2-1ubuntu2.4', 'cves': ['CVE-2026-32665', 'CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-55973', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '26.04', 'pkgname': 'unbound-anchor', 'pkgver': '1.24.2-1ubuntu2.4', 'cves': ['CVE-2026-32665', 'CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-55973', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']},
    {'osver': '26.04', 'pkgname': 'unbound-host', 'pkgver': '1.24.2-1ubuntu2.4', 'cves': ['CVE-2026-32665', 'CVE-2026-40691', 'CVE-2026-44690', 'CVE-2026-50252', 'CVE-2026-55973', 'CVE-2026-80225', 'CVE-2026-81634', 'CVE-2026-85501']}
];

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'];
  if (osver && pkgname && pkgver) {
    if (deb_check(release:osver, prefix:pkgname, reference:pkgver, cves:cves)) 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, 'libunbound2 / libunbound8 / python-unbound / python3-unbound / etc');
}