Ubuntu 18.04 LTS : Linux kernel vulnerability and regression (USN-4184-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4184-2. 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(131012);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/28");

  script_cve_id("CVE-2019-0155");
  script_xref(name:"USN", value:"4184-2");

  script_name(english:"Ubuntu 18.04 LTS : Linux kernel vulnerability and regression (USN-4184-2)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 LTS host has a package installed that is affected by a vulnerability as referenced in the
USN-4184-2 advisory.

    USN-4184-1 fixed vulnerabilities in the Linux kernel. It was discovered that the kernel fix for
    CVE-2019-0155 (i915 missing Blitter Command Streamer check) was incomplete on 64-bit Intel x86 systems.
    Also, the update introduced a regression that broke KVM guests where extended page tables (EPT) are
    disabled or not supported. This update addresses both issues.

    We apologize for the inconvenience.

    Original advisory details:

    Stephan van Schaik, Alyssa Milburn, Sebastian sterlund, Pietro Frigo,

    Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Giorgi Maisuradze, Moritz

    Lipp, Michael Schwarz, Daniel Gruss, and Jo Van Bulck discovered that Intel

    processors using Transactional Synchronization Extensions (TSX) could

    expose memory contents previously stored in microarchitectural buffers to a

    malicious process that is executing on the same CPU core. A local attacker

    could use this to expose sensitive information. (CVE-2019-11135)

    It was discovered that the Intel i915 graphics chipsets allowed userspace

    to modify page table entries via writes to MMIO from the Blitter Command

    Streamer and expose kernel memory information. A local attacker could use

    this to expose sensitive information or possibly elevate privileges.

    (CVE-2019-0155)

    Deepak Gupta discovered that on certain Intel processors, the Linux kernel

    did not properly perform invalidation on page table updates by virtual

    guest operating systems. A local attacker in a guest VM could use this to

    cause a denial of service (host system crash). (CVE-2018-12207)

    It was discovered that the Intel i915 graphics chipsets could cause a

    system hang when userspace performed a read from GT memory mapped input

    output (MMIO) when the product is in certain low power states. A local

    attacker could use this to cause a denial of service. (CVE-2019-0154)

    Hui Peng discovered that the Atheros AR6004 USB Wi-Fi device driver for the

    Linux kernel did not properly validate endpoint descriptors returned by the

    device. A physically proximate attacker could use this to cause a denial of

    service (system crash). (CVE-2019-15098)

    Jann Horn discovered a reference count underflow in the shiftfs

    implementation in the Linux kernel. A local attacker could use this to

    cause a denial of service (system crash) or possibly execute arbitrary

    code. (CVE-2019-15791)

    Jann Horn discovered a type confusion vulnerability in the shiftfs

    implementation in the Linux kernel. A local attacker could use this to

    cause a denial of service (system crash) or possibly execute arbitrary

    code. (CVE-2019-15792)

    Jann Horn discovered that the shiftfs implementation in the Linux kernel

    did not use the correct file system uid/gid when the user namespace of a

    lower file system is not in the init user namespace. A local attacker could

    use this to possibly bypass DAC permissions or have some other unspecified

    impact. (CVE-2019-15793)

    Ori Nimron discovered that the AX25 network protocol implementation in the

    Linux kernel did not properly perform permissions checks. A local attacker

    could use this to create a raw socket. (CVE-2019-17052)

    Ori Nimron discovered that the IEEE 802.15.4 Low-Rate Wireless network

    protocol implementation in the Linux kernel did not properly perform

    permissions checks. A local attacker could use this to create a raw socket.

    (CVE-2019-17053)

    Ori Nimron discovered that the Appletalk network protocol implementation in

    the Linux kernel did not properly perform permissions checks. A local

    attacker could use this to create a raw socket. (CVE-2019-17054)

    Ori Nimron discovered that the modular ISDN network protocol implementation

    in the Linux kernel did not properly perform permissions checks. A local

    attacker could use this to create a raw socket. (CVE-2019-17055)

    Ori Nimron discovered that the Near field Communication (NFC) network

    protocol implementation in the Linux kernel did not properly perform

    permissions checks. A local attacker could use this to create a raw socket.

    (CVE-2019-17056)

    Nico Waisman discovered that a buffer overflow existed in the Realtek Wi-Fi

    driver for the Linux kernel when handling Notice of Absence frames. A

    physically proximate attacker could use this to cause a denial of service

    (system crash) or possibly execute arbitrary code. (CVE-2019-17666)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue 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-4184-2");
  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: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-2019-0155");

  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:"2019/08/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/11/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/11/14");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-1028-oem-osp1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-36-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-36-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-5.0.0-36-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': '5.0.0-36',
      'generic-lpae': '5.0.0-36',
      'lowlatency': '5.0.0-36',
      'oem-osp1': '5.0.0-1028'
    }
  }
};

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-4184-2');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2019-0155');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-4184-2');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}