Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Intel Microcode vulnerabilities (USN-3756-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3756-1. 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(112151);
  script_version("1.11");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id("CVE-2018-3639", "CVE-2018-3640", "CVE-2018-3646");
  script_xref(name:"USN", value:"3756-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS : Intel Microcode vulnerabilities (USN-3756-1)");

  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 host has a package installed that is affected by multiple
vulnerabilities as referenced in the USN-3756-1 advisory.

    It was discovered that memory present in the L1 data cache of an Intel CPU core may be exposed to a
    malicious process that is executing on the CPU core. This vulnerability is also known as L1 Terminal Fault
    (L1TF). A local attacker in a guest virtual machine could use this to expose sensitive information (memory
    from other guests or the host OS). (CVE-2018-3646)

    Jann Horn and Ken Johnson discovered that microprocessors utilizing speculative execution of a memory read
    may allow unauthorized memory reads via a sidechannel attack. This flaw is known as Spectre Variant 4. A
    local attacker could use this to expose sensitive information, including kernel memory. (CVE-2018-3639)

    Zdenek Sojka, Rudolf Marek, Alex Zuepke, and Innokentiy Sennovskiy discovered that microprocessors that
    perform speculative reads of system registers may allow unauthorized disclosure of system parameters via a
    sidechannel attack. This vulnerability is also known as Rogue System Register Read (RSRE). An attacker
    could use this to expose sensitive information. (CVE-2018-3640)

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-3756-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected intel-microcode package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/Au:N/C:C/I:N/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2018-3646");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"in_the_news", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/05/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/08/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/08/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:intel-microcode");
  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:"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) 2018-2024 Canonical, Inc. / NASL script (C) 2018-2024 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 || '18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 14.04 / 16.04 / 18.04', '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': 'intel-microcode', 'pkgver': '3.20180807a.0ubuntu0.14.04.1'},
    {'osver': '16.04', 'pkgname': 'intel-microcode', 'pkgver': '3.20180807a.0ubuntu0.16.04.1'},
    {'osver': '18.04', 'pkgname': 'intel-microcode', 'pkgver': '3.20180807a.0ubuntu0.18.04.1'}
];

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 (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  var extra = '';
  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, 'intel-microcode');
}