Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-4368-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4368-1. 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(136733);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2019-19769",
    "CVE-2020-11494",
    "CVE-2020-11565",
    "CVE-2020-11608",
    "CVE-2020-11609",
    "CVE-2020-11668",
    "CVE-2020-11669",
    "CVE-2020-12657"
  );
  script_xref(name:"USN", value:"4368-1");

  script_name(english:"Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-4368-1)");

  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 18.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in
the USN-4368-1 advisory.

    Tristan Madani discovered that the file locking implementation in the Linux kernel contained a race
    condition. A local attacker could possibly use this to cause a denial of service or expose sensitive
    information. (CVE-2019-19769)

    It was discovered that the Serial CAN interface driver in the Linux kernel did not properly initialize
    data. A local attacker could use this to expose sensitive information (kernel memory). (CVE-2020-11494)

    It was discovered that the linux kernel did not properly validate certain mount options to the tmpfs
    virtual memory file system. A local attacker with the ability to specify mount options could use this to
    cause a denial of service (system crash). (CVE-2020-11565)

    It was discovered that the OV51x USB Camera device driver in the Linux kernel did not properly validate
    device metadata. A physically proximate attacker could use this to cause a denial of service (system
    crash). (CVE-2020-11608)

    It was discovered that the STV06XX USB Camera device driver in the Linux kernel did not properly validate
    device metadata. A physically proximate attacker could use this to cause a denial of service (system
    crash). (CVE-2020-11609)

    It was discovered that the Xirlink C-It USB Camera device driver in the Linux kernel did not properly
    validate device metadata. A physically proximate attacker could use this to cause a denial of service
    (system crash). (CVE-2020-11668)

    David Gibson discovered that the Linux kernel on Power9 CPUs did not properly save and restore Authority
    Mask registers state in some situations. A local attacker in a guest VM could use this to cause a denial
    of service (host system crash). (CVE-2020-11669)

    It was discovered that the block layer in the Linux kernel contained a race condition leading to a use-
    after-free vulnerability. A local attacker could possibly use this to cause a denial of service (system
    crash) or execute arbitrary code. (CVE-2020-12657)

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-4368-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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-2019-19769");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2020-12657");

  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:"2019/12/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-1037-gke");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-1052-oem-osp1");
  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) 2020-2024 Canonical, Inc. / NASL script (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('debian_package.inc');
include('ksplice.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 (! ('18.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 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 kernel_mappings = {
  '18.04': {
    '5.0.0': {
      'gke': '5.0.0-1037',
      'oem-osp1': '5.0.0-1052'
    }
  }
};

var host_kernel_release = get_kb_item('Host/uptrack-uname-r');
if (empty_or_null(host_kernel_release)) host_kernel_release = get_kb_item_or_exit('Host/uname-r');
var host_kernel_base_version = get_kb_item_or_exit('Host/Debian/kernel-base-version');
var host_kernel_type = get_kb_item_or_exit('Host/Debian/kernel-type');
if(empty_or_null(kernel_mappings[os_release][host_kernel_base_version][host_kernel_type])) audit(AUDIT_INST_VER_NOT_VULN, 'kernel ' + host_kernel_release);

var extra = '';
var kernel_fixed_version = kernel_mappings[os_release][host_kernel_base_version][host_kernel_type] + "-" + host_kernel_type;
if (deb_ver_cmp(ver1:host_kernel_release, ver2:kernel_fixed_version) < 0)
{
  extra += 'Running Kernel level of ' + host_kernel_release + ' does not meet the minimum fixed level of ' + kernel_fixed_version + ' for this advisory.\n\n';
}
  else
{
  audit(AUDIT_PATCH_INSTALLED, 'Kernel package for USN-4368-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2019-19769', 'CVE-2020-11494', 'CVE-2020-11565', 'CVE-2020-11608', 'CVE-2020-11609', 'CVE-2020-11668', 'CVE-2020-11669', 'CVE-2020-12657');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-4368-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : extra
  );
  exit(0);
}