Ubuntu 16.04 LTS : Linux kernel (HWE) vulnerabilities (USN-3847-2)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3847-2. 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(119828);
  script_version("1.9");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id(
    "CVE-2018-10902",
    "CVE-2018-12896",
    "CVE-2018-14734",
    "CVE-2018-16276",
    "CVE-2018-18445",
    "CVE-2018-18690",
    "CVE-2018-18710"
  );
  script_xref(name:"USN", value:"3847-2");

  script_name(english:"Ubuntu 16.04 LTS : Linux kernel (HWE) vulnerabilities (USN-3847-2)");

  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 16.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in
the USN-3847-2 advisory.

  - It was found that the raw midi kernel driver does not protect against concurrent access which leads to a
    double realloc (double free) in snd_rawmidi_input_params() and snd_rawmidi_output_status() which are part
    of snd_rawmidi_ioctl() handler in rawmidi.c file. A malicious local attacker could possibly use this for
    privilege escalation. (CVE-2018-10902)

  - An issue was discovered in the Linux kernel through 4.17.3. An Integer Overflow in kernel/time/posix-
    timers.c in the POSIX timer code is caused by the way the overrun accounting works. Depending on interval
    and expiry time values, the overrun can be larger than INT_MAX, but the accounting is int based. This
    basically makes the accounting values, which are visible to user space via timer_getoverrun(2) and
    siginfo::si_overrun, random. For example, a local user can cause a denial of service (signed integer
    overflow) via crafted mmap, futex, timer_create, and timer_settime system calls. (CVE-2018-12896)

  - drivers/infiniband/core/ucma.c in the Linux kernel through 4.17.11 allows ucma_leave_multicast to access a
    certain data structure after a cleanup step in ucma_process_join, which allows attackers to cause a denial
    of service (use-after-free). (CVE-2018-14734)

  - An issue was discovered in yurex_read in drivers/usb/misc/yurex.c in the Linux kernel before 4.17.7. Local
    attackers could use user access read/writes with incorrect bounds checking in the yurex USB driver to
    crash the kernel or potentially escalate privileges. (CVE-2018-16276)

  - In the Linux kernel 4.14.x, 4.15.x, 4.16.x, 4.17.x, and 4.18.x before 4.18.13, faulty computation of
    numeric bounds in the BPF verifier permits out-of-bounds memory accesses because
    adjust_scalar_min_max_vals in kernel/bpf/verifier.c mishandles 32-bit right shifts. (CVE-2018-18445)

  - In the Linux kernel before 4.17, a local attacker able to set attributes on an xfs filesystem could make
    this filesystem non-operational until the next mount by triggering an unchecked error condition during an
    xfs attribute change, because xfs_attr_shortform_addname in fs/xfs/libxfs/xfs_attr.c mishandles
    ATTR_REPLACE operations with conversion of an attr from short to long form. (CVE-2018-18690)

  - An issue was discovered in the Linux kernel through 4.19. An information leak in cdrom_ioctl_select_disc
    in drivers/cdrom/cdrom.c could be used by local attackers to read kernel memory because a cast from
    unsigned long to int interferes with bounds checking. This is similar to CVE-2018-10940 and
    CVE-2018-16658. (CVE-2018-18710)

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-3847-2");
  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-2018-18445");

  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:"2018/07/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2018/12/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2018/12/21");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1026-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1031-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1036-azure");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-43-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-43-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-43-lowlatency");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-: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", "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 (! ('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 kernel_mappings = {
  '16.04': {
    '4.15.0': {
      'generic': '4.15.0-43',
      'generic-lpae': '4.15.0-43',
      'lowlatency': '4.15.0-43',
      'gcp': '4.15.0-1026',
      'aws': '4.15.0-1031',
      'azure': '4.15.0-1036'
    }
  }
};

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-3847-2');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2018-10902', 'CVE-2018-12896', 'CVE-2018-14734', 'CVE-2018-16276', 'CVE-2018-18445', 'CVE-2018-18690', 'CVE-2018-18710');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-3847-2');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}