Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS : HTMLDOC vulnerabilities (USN-7189-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-7189-1. 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(213544);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/09/03");

  script_cve_id(
    "CVE-2021-20308",
    "CVE-2021-23158",
    "CVE-2021-23191",
    "CVE-2021-23206",
    "CVE-2021-26252",
    "CVE-2021-26259",
    "CVE-2021-26948",
    "CVE-2021-34119",
    "CVE-2021-34121",
    "CVE-2021-40985",
    "CVE-2021-43579"
  );
  script_xref(name:"USN", value:"7189-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 20.04 LTS : HTMLDOC vulnerabilities (USN-7189-1)");

  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 host has packages installed that are affected by
multiple vulnerabilities as referenced in the USN-7189-1 advisory.

    It was discovered that HTMLDOC incorrectly handled certain inputs, which could lead to an integer
    overflow. An attacker could potentially use this issue to cause a denial of service or execute arbitrary
    code. (CVE-2021-20308)

    It was discovered that HTMLDOC incorrectly handled memory in pspdf_export, which could lead to a double-
    free. An attacker could potentially use this issue to cause a denial of service or execute arbitrary code.
    (CVE-2021-23158)

    It was discovered that HTMLDOC incorrectly handled memory when loading a JPEG image, which could lead to a
    NULL pointer dereference. An attacker could potentially use this issue to cause a denial of service.
    (CVE-2021-23191, CVE-2021-26948)

    It was discovered that HTMLDOC incorrectly handled certain inputs, which could lead to a stack buffer
    overflow. An attacker could potentially use this issue to cause a denial of service or execute arbitrary
    code. (CVE-2021-23206, CVE-2021-40985, CVE-2021-43579)

    It was discovered that HTMLDOC incorrectly handled memory in pdpdf_prepare_page and render_table_row,
    which could lead to a heap buffer overflow. An attacker could potentially use this issue to cause a denial
    of service or execute arbitrary code. (CVE-2021-26252, CVE-2021-26259)

    It was discovered that HTMLDOC incorrectly handled memory in parse_paragraph, which could lead to a heap
    buffer overflow. An attacker could potentially use this issue to cause a denial of service or execute
    arbitrary code. This issue only affected Ubuntu 20.04 LTS. (CVE-2021-34119)

    It was discovered that HTMLDOC incorrectly handled memory in parse_tree. An attacker could potentially use
    this issue to leak sensitive information. (CVE-2021-34121)

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-7189-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected htmldoc and / or htmldoc-common packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2021-23158");

  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:"2021/04/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/01/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/01/08");

  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:"p-cpe:/a:canonical:ubuntu_linux:htmldoc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:htmldoc-common");
  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) 2025 Canonical, Inc. / NASL script (C) 2025 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 (! ('14.04' >< os_release || '16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04 / 20.04', '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': '14.04', 'pkgname': 'htmldoc', 'pkgver': '1.8.27-8ubuntu1+esm3', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '14.04', 'pkgname': 'htmldoc-common', 'pkgver': '1.8.27-8ubuntu1+esm3', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '16.04', 'pkgname': 'htmldoc', 'pkgver': '1.8.27-8ubuntu1.1+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '16.04', 'pkgname': 'htmldoc-common', 'pkgver': '1.8.27-8ubuntu1.1+esm2', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '18.04', 'pkgname': 'htmldoc', 'pkgver': '1.9.2-1ubuntu0.2+esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '18.04', 'pkgname': 'htmldoc-common', 'pkgver': '1.9.2-1ubuntu0.2+esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '20.04', 'pkgname': 'htmldoc', 'pkgver': '1.9.7-1ubuntu0.3+esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34119', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']},
    {'osver': '20.04', 'pkgname': 'htmldoc-common', 'pkgver': '1.9.7-1ubuntu0.3+esm1', 'ubuntu_pro': TRUE, 'cves': ['CVE-2021-20308', 'CVE-2021-23158', 'CVE-2021-23191', 'CVE-2021-23206', 'CVE-2021-26252', 'CVE-2021-26259', 'CVE-2021-26948', 'CVE-2021-34119', 'CVE-2021-34121', 'CVE-2021-40985', 'CVE-2021-43579']}
];

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, 'htmldoc / htmldoc-common');
}