Ubuntu 14.04 LTS / 16.04 LTS / 17.04 : xorg-server, xorg-server-hwe-16.04, xorg-server-lts-xenial vulnerabilities (USN-3453-1)

2017-10-13T00:00:00
ID UBUNTU_USN-3453-1.NASL
Type nessus
Reporter Tenable
Modified 2018-12-01T00:00:00

Description

Michal Srb discovered that the X.Org X server incorrectly handled shared memory segments. An attacker able to connect to an X server, either locally or remotely, could use this issue to crash the server, or possibly replace shared memory segments of other X clients in the same session. (CVE-2017-13721)

Michal Srb discovered that the X.Org X server incorrectly handled XKB buffers. An attacker able to connect to an X server, either locally or remotely, could use this issue to crash the server, or possibly execute arbitrary code. (CVE-2017-13723).

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.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3453-1. 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(103834);
  script_version("3.7");
  script_cvs_date("Date: 2018/12/01 15:12:41");

  script_cve_id("CVE-2017-13721", "CVE-2017-13723");
  script_xref(name:"USN", value:"3453-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 17.04 : xorg-server, xorg-server-hwe-16.04, xorg-server-lts-xenial vulnerabilities (USN-3453-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Michal Srb discovered that the X.Org X server incorrectly handled
shared memory segments. An attacker able to connect to an X server,
either locally or remotely, could use this issue to crash the server,
or possibly replace shared memory segments of other X clients in the
same session. (CVE-2017-13721)

Michal Srb discovered that the X.Org X server incorrectly handled XKB
buffers. An attacker able to connect to an X server, either locally or
remotely, could use this issue to crash the server, or possibly
execute arbitrary code. (CVE-2017-13723).

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://usn.ubuntu.com/3453-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected xserver-xorg-core, xserver-xorg-core-hwe-16.04 and
/ or xserver-xorg-core-lts-xenial 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:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  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-lts-xenial");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:17.04");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/10/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/10/13");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2017-2018 Canonical, Inc. / NASL script (C) 2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! ereg(pattern:"^(14\.04|16\.04|17\.04)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04 / 16.04 / 17.04", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) audit(AUDIT_PACKAGE_LIST_MISSING);

cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"14.04", pkgname:"xserver-xorg-core", pkgver:"2:1.15.1-0ubuntu2.10")) flag++;
if (ubuntu_check(osver:"14.04", pkgname:"xserver-xorg-core-lts-xenial", pkgver:"2:1.18.3-1ubuntu2.3~trusty3")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"xserver-xorg-core", pkgver:"2:1.18.4-0ubuntu0.6")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"xserver-xorg-core-hwe-16.04", pkgver:"2:1.19.3-1ubuntu1~16.04.3")) flag++;
if (ubuntu_check(osver:"17.04", pkgname:"xserver-xorg-core", pkgver:"2:1.19.3-1ubuntu1.2")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "xserver-xorg-core / xserver-xorg-core-hwe-16.04 / etc");
}