Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : X.Org X Server vulnerabilities (USN-4488-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4488-1. 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(140267);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id(
    "CVE-2020-14346",
    "CVE-2020-14347",
    "CVE-2020-14361",
    "CVE-2020-14362"
  );
  script_xref(name:"USN", value:"4488-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : X.Org X Server vulnerabilities (USN-4488-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"Jan-Niklas Sohn discovered that the X.Org X Server incorrectly handled
the input extension protocol. A local attacker could possibly use this
issue to escalate privileges. (CVE-2020-14346) Jan-Niklas Sohn
discovered that the X.Org X Server incorrectly initialized memory. A
local attacker could possibly use this issue to obtain sensitive
information. (CVE-2020-14347) Jan-Niklas Sohn discovered that the
X.Org X Server incorrectly handled the XkbSelectEvents function. A
local attacker could possibly use this issue to escalate privileges.
(CVE-2020-14361) Jan-Niklas Sohn discovered that the X.Org X Server
incorrectly handled the XRecordRegisterClients function. A local
attacker could possibly use this issue to escalate privileges.
(CVE-2020-14362).

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-4488-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/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:"cvss_score_source", value:"CVE-2020-14362");

  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:"2020/08/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/09/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/09/04");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-core-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-core-hwe-18.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-core-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-dev-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-dev-hwe-18.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-legacy");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-legacy-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-legacy-hwe-18.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xorg-xmir");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xvfb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xwayland");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xwayland-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xwayland-hwe-18.04");
  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:xdmx");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xdmx-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xmir");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xmir-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xnest");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xorg-server-source");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xorg-server-source-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xorg-server-source-hwe-18.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xephyr");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xephyr-hwe-16.04");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:xserver-xephyr-hwe-18.04");
  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) 2020-2023 Canonical, Inc. / NASL script (C) 2020-2023 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 (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 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 pkgs = [
    {'osver': '16.04', 'pkgname': 'xdmx', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xdmx-tools', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xmir', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xmir-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xnest', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xorg-server-source', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xorg-server-source-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xserver-common', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xephyr', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xephyr-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-core', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-core-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-core-udeb', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-dev', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-dev-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-legacy', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-legacy-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '16.04', 'pkgname': 'xserver-xorg-xmir', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xvfb', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xwayland', 'pkgver': '2:1.18.4-0ubuntu0.9'},
    {'osver': '16.04', 'pkgname': 'xwayland-hwe-16.04', 'pkgver': '2:1.19.6-1ubuntu4.1~16.04.3'},
    {'osver': '18.04', 'pkgname': 'xdmx', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xdmx-tools', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xmir', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xnest', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xorg-server-source', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xorg-server-source-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '18.04', 'pkgname': 'xserver-common', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xephyr', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xephyr-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-core', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-core-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-core-udeb', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-dev', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-dev-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-legacy', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-legacy-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '18.04', 'pkgname': 'xserver-xorg-xmir', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xvfb', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xwayland', 'pkgver': '2:1.19.6-1ubuntu4.5'},
    {'osver': '18.04', 'pkgname': 'xwayland-hwe-18.04', 'pkgver': '2:1.20.8-2ubuntu2.2~18.04.2'},
    {'osver': '20.04', 'pkgname': 'xdmx', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xdmx-tools', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xnest', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xorg-server-source', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-common', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-xephyr', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-xorg-core', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-xorg-core-udeb', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-xorg-dev', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xserver-xorg-legacy', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xvfb', 'pkgver': '2:1.20.8-2ubuntu2.3'},
    {'osver': '20.04', 'pkgname': 'xwayland', 'pkgver': '2:1.20.8-2ubuntu2.3'}
];

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_WARNING,
    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, 'xdmx / xdmx-tools / xmir / xmir-hwe-16.04 / xnest / etc');
}