Ubuntu 18.04 LTS : Linux kernel (HWE) vulnerabilities (USN-4069-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4069-2. 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(127792);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id(
    "CVE-2019-11487",
    "CVE-2019-11599",
    "CVE-2019-11833",
    "CVE-2019-11884"
  );
  script_xref(name:"USN", value:"4069-2");

  script_name(english:"Ubuntu 18.04 LTS : Linux kernel (HWE) vulnerabilities (USN-4069-2)");

  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-4069-2 advisory.

  - The Linux kernel before 5.1-rc5 allows page->_refcount reference count overflow, with resultant use-after-
    free issues, if about 140 GiB of RAM exists. This is related to fs/fuse/dev.c, fs/pipe.c, fs/splice.c,
    include/linux/mm.h, include/linux/pipe_fs_i.h, kernel/trace/trace.c, mm/gup.c, and mm/hugetlb.c. It can
    occur with FUSE requests. (CVE-2019-11487)

  - The coredump implementation in the Linux kernel before 5.0.10 does not use locking or other mechanisms to
    prevent vma layout or vma flags changes while it runs, which allows local users to obtain sensitive
    information, cause a denial of service, or possibly have unspecified other impact by triggering a race
    condition with mmget_not_zero or get_task_mm calls. This is related to fs/userfaultfd.c, mm/mmap.c,
    fs/proc/task_mmu.c, and drivers/infiniband/core/uverbs_main.c. (CVE-2019-11599)

  - fs/ext4/extents.c in the Linux kernel through 5.1.2 does not zero out the unused memory region in the
    extent tree block, which might allow local users to obtain sensitive information by reading uninitialized
    data in the filesystem. (CVE-2019-11833)

  - The do_hidp_sock_ioctl function in net/bluetooth/hidp/sock.c in the Linux kernel before 5.0.15 allows a
    local user to obtain potentially sensitive information from kernel stack memory via a HIDPCONNADD command,
    because a name field may not end with a '\0' character. (CVE-2019-11884)

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-4069-2");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-11487");

  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:"2019/04/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/08/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/08/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-23-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-23-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-23-lowlatency");
  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) 2019-2024 Canonical, Inc. / NASL script (C) 2019-2024 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': {
      'generic': '5.0.0-23',
      'generic-lpae': '5.0.0-23',
      'lowlatency': '5.0.0-23'
    }
  }
};

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 = 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-4069-2');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2019-11487', 'CVE-2019-11599', 'CVE-2019-11833', 'CVE-2019-11884');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-4069-2');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}