Ubuntu 16.04 ESM : Intel Microcode vulnerabilities (USN-5535-1)

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5535-1. 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(163520);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/28");

  script_cve_id(
    "CVE-2021-0127",
    "CVE-2021-0145",
    "CVE-2021-0146",
    "CVE-2021-33117",
    "CVE-2021-33120",
    "CVE-2022-21123",
    "CVE-2022-21125",
    "CVE-2022-21127",
    "CVE-2022-21151",
    "CVE-2022-21166"
  );
  script_xref(name:"USN", value:"5535-1");

  script_name(english:"Ubuntu 16.04 ESM : Intel Microcode vulnerabilities (USN-5535-1)");

  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 16.04 ESM host has a package installed that is affected by multiple vulnerabilities as referenced in
the USN-5535-1 advisory.

    Joseph Nuzman discovered that some Intel processors did not properly initialise shared resources. A local
    attacker could use this to obtain sensitive information. (CVE-2021-0145)

    Mark Ermolov, Dmitry Sklyarov and Maxim Goryachy discovered that some Intel processors did not prevent
    test and debug logic from being activated at runtime. A local attacker could use this to escalate
    privileges. (CVE-2021-0146)

    It was discovered that some Intel processors did not implement sufficient control flow management. A local
    attacker could use this to cause a denial of service (system crash). (CVE-2021-0127)

    It was discovered that some Intel processors did not completely perform cleanup actions on multi-core
    shared buffers. A local attacker could possibly use this to expose sensitive information. (CVE-2022-21123,
    CVE-2022-21127)

    It was discovered that some Intel processors did not completely perform cleanup actions on
    microarchitectural fill buffers. A local attacker could possibly use this to expose sensitive information.
    (CVE-2022-21125)

    Alysa Milburn, Jason Brandt, Avishai Redelman and Nir Lavi discovered that some Intel processors
    improperly optimised security-critical code. A local attacker could possibly use this to expose sensitive
    information. (CVE-2022-21151)

    It was discovered that some Intel processors did not properly perform cleanup during specific special
    register write operations. A local attacker could possibly use this to expose sensitive information.
    (CVE-2022-21166)

    It was discovered that some Intel processors did not properly restrict access in some situations. A local
    attacker could use this to obtain sensitive information. (CVE-2021-33117)

    Brandon Miller discovered that some Intel processors did not properly restrict access in some situations.
    A local attacker could use this to obtain sensitive information or a remote attacker could use this to
    cause a denial of service (system crash). (CVE-2021-33120)

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-5535-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected intel-microcode package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:P/AC:L/PR:N/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-2021-33120");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2021-0146");

  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:"2021/11/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/07/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/07/28");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:esm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:intel-microcode");
  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) 2022-2024 Canonical, Inc. / NASL script (C) 2022-2024 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 (! ('16.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 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 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': '16.04', 'pkgname': 'intel-microcode', 'pkgver': '3.20220510.0ubuntu0.16.04.1+esm1', 'ubuntu_pro': TRUE}
];

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, 'intel-microcode');
}