Ubuntu 14.04 LTS / 18.04 LTS / 20.04 LTS : Libcroco vulnerabilities (USN-6958-1)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-6958-1. 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(205444);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2017-7960",
    "CVE-2017-8834",
    "CVE-2017-8871",
    "CVE-2020-12825"
  );
  script_xref(name:"USN", value:"6958-1");

  script_name(english:"Ubuntu 14.04 LTS / 18.04 LTS / 20.04 LTS : Libcroco vulnerabilities (USN-6958-1)");

  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 / 18.04 LTS / 20.04 LTS host has packages installed that are affected by multiple
vulnerabilities as referenced in the USN-6958-1 advisory.

    It was discovered that Libcroco was incorrectly accessing data structures when reading bytes from memory,
    which could cause a heap buffer overflow. An attacker could possibly use this issue to cause a denial of
    service. This issue only affected Ubuntu 14.04 LTS. (CVE-2017-7960)

    It was discovered that Libcroco was incorrectly handling invalid UTF-8 values when processing CSS files.
    An attacker could possibly use this issue to cause a denial of service. (CVE-2017-8834, CVE-2017-8871)

    It was discovered that Libcroco was incorrectly implementing recursion in one of its parsing functions,
    which could cause an infinite recursion loop and a stack overflow due to stack consumption. An attacker
    could possibly use this issue to cause a denial of service. (CVE-2020-12825)

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-6958-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected libcroco-tools, libcroco3 and / or libcroco3-dev packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/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:R/S:U/C:N/I:L/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-2020-12825");

  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:"2017/04/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/08/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/08/13");

  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: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:libcroco-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcroco3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libcroco3-dev");
  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", "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 || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 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': 'libcroco-tools', 'pkgver': '0.6.8-2ubuntu1+esm1', 'ubuntu_pro': TRUE},
    {'osver': '14.04', 'pkgname': 'libcroco3', 'pkgver': '0.6.8-2ubuntu1+esm1', 'ubuntu_pro': TRUE},
    {'osver': '14.04', 'pkgname': 'libcroco3-dev', 'pkgver': '0.6.8-2ubuntu1+esm1', 'ubuntu_pro': TRUE},
    {'osver': '18.04', 'pkgname': 'libcroco-tools', 'pkgver': '0.6.12-2ubuntu0.1~esm1', 'ubuntu_pro': TRUE},
    {'osver': '18.04', 'pkgname': 'libcroco3', 'pkgver': '0.6.12-2ubuntu0.1~esm1', 'ubuntu_pro': TRUE},
    {'osver': '18.04', 'pkgname': 'libcroco3-dev', 'pkgver': '0.6.12-2ubuntu0.1~esm1', 'ubuntu_pro': TRUE},
    {'osver': '20.04', 'pkgname': 'libcroco-tools', 'pkgver': '0.6.13-1ubuntu0.1', 'ubuntu_pro': FALSE},
    {'osver': '20.04', 'pkgname': 'libcroco3', 'pkgver': '0.6.13-1ubuntu0.1', 'ubuntu_pro': FALSE},
    {'osver': '20.04', 'pkgname': 'libcroco3-dev', 'pkgver': '0.6.13-1ubuntu0.1', 'ubuntu_pro': FALSE}
];

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'];
  var pro_required = NULL;
  if (!empty_or_null(package_array['ubuntu_pro'])) pro_required = package_array['ubuntu_pro'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) {
        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_WARNING,
    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, 'libcroco-tools / libcroco3 / libcroco3-dev');
}