Ubuntu 14.04 LTS / 16.04 LTS : libxml2 vulnerabilities (USN-3424-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3424-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include('compat.inc');

if (description)
{
  script_id(103327);
  script_version("3.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id(
    "CVE-2017-0663",
    "CVE-2017-7375",
    "CVE-2017-7376",
    "CVE-2017-9047",
    "CVE-2017-9048",
    "CVE-2017-9049",
    "CVE-2017-9050"
  );
  script_xref(name:"USN", value:"3424-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS : libxml2 vulnerabilities (USN-3424-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"It was discovered that a type confusion error existed in libxml2. An
attacker could use this to specially construct XML data that could
cause a denial of service or possibly execute arbitrary code.
(CVE-2017-0663)

It was discovered that libxml2 did not properly validate parsed entity
references. An attacker could use this to specially construct XML data
that could expose sensitive information. (CVE-2017-7375)

It was discovered that a buffer overflow existed in libxml2 when
handling HTTP redirects. An attacker could use this to specially
construct XML data that could cause a denial of service or possibly
execute arbitrary code. (CVE-2017-7376)

Marcel Bohme and Van-Thuan Pham discovered a buffer overflow in
libxml2 when handling elements. An attacker could use this to
specially construct XML data that could cause a denial of service or
possibly execute arbitrary code. (CVE-2017-9047)

Marcel Bohme and Van-Thuan Pham discovered a buffer overread in
libxml2 when handling elements. An attacker could use this to
specially construct XML data that could cause a denial of service.
(CVE-2017-9048)

Marcel Bohme and Van-Thuan Pham discovered multiple buffer overreads
in libxml2 when handling parameter-entity references. An attacker
could use these to specially construct XML data that could cause a
denial of service. (CVE-2017-9049, CVE-2017-9050).

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-3424-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/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: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-2017-7376");

  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:"2017/05/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/09/18");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/09/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libxml2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libxml2-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libxml2-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libxml2-utils");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-libxml2");
  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:"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) 2017-2023 Canonical, Inc. / NASL script (C) 2017-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info.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)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04', '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': 'libxml2', 'pkgver': '2.9.1+dfsg1-3ubuntu4.10'},
    {'osver': '14.04', 'pkgname': 'libxml2-dev', 'pkgver': '2.9.1+dfsg1-3ubuntu4.10'},
    {'osver': '14.04', 'pkgname': 'libxml2-udeb', 'pkgver': '2.9.1+dfsg1-3ubuntu4.10'},
    {'osver': '14.04', 'pkgname': 'libxml2-utils', 'pkgver': '2.9.1+dfsg1-3ubuntu4.10'},
    {'osver': '14.04', 'pkgname': 'python-libxml2', 'pkgver': '2.9.1+dfsg1-3ubuntu4.10'},
    {'osver': '16.04', 'pkgname': 'libxml2', 'pkgver': '2.9.3+dfsg1-1ubuntu0.3'},
    {'osver': '16.04', 'pkgname': 'libxml2-dev', 'pkgver': '2.9.3+dfsg1-1ubuntu0.3'},
    {'osver': '16.04', 'pkgname': 'libxml2-udeb', 'pkgver': '2.9.3+dfsg1-1ubuntu0.3'},
    {'osver': '16.04', 'pkgname': 'libxml2-utils', 'pkgver': '2.9.3+dfsg1-1ubuntu0.3'},
    {'osver': '16.04', 'pkgname': 'python-libxml2', 'pkgver': '2.9.3+dfsg1-1ubuntu0.3'}
];

var flag = 0;
foreach 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 (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'libxml2 / libxml2-dev / libxml2-udeb / libxml2-utils / etc');
}