Ubuntu 16.04 LTS : Linux kernel (HWE) vulnerabilities (USN-3871-4)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3871-4. 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(121594);
  script_version("1.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/09");

  script_cve_id(
    "CVE-2018-10876",
    "CVE-2018-10877",
    "CVE-2018-10878",
    "CVE-2018-10879",
    "CVE-2018-10880",
    "CVE-2018-10882",
    "CVE-2018-10883",
    "CVE-2018-14625",
    "CVE-2018-16882",
    "CVE-2018-17972",
    "CVE-2018-18281",
    "CVE-2018-19407",
    "CVE-2018-9516"
  );
  script_xref(name:"USN", value:"3871-4");

  script_name(english:"Ubuntu 16.04 LTS : Linux kernel (HWE) vulnerabilities (USN-3871-4)");

  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-3871-4 advisory.

  - A flaw was found in Linux kernel in the ext4 filesystem code. A use-after-free is possible in
    ext4_ext_remove_space() function when mounting and operating a crafted ext4 image. (CVE-2018-10876)

  - Linux kernel ext4 filesystem is vulnerable to an out-of-bound access in the ext4_ext_drop_refs() function
    when operating on a crafted ext4 filesystem image. (CVE-2018-10877)

  - A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bounds write and
    a denial of service or unspecified other impact is possible by mounting and operating a crafted ext4
    filesystem image. (CVE-2018-10878)

  - A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause a use-after-free in
    ext4_xattr_set_entry function and a denial of service or unspecified other impact may occur by renaming a
    file in a crafted ext4 filesystem image. (CVE-2018-10879)

  - Linux kernel is vulnerable to a stack-out-of-bounds write in the ext4 filesystem code when mounting and
    writing to a crafted ext4 image in ext4_update_inline_data(). An attacker could use this to cause a system
    crash and a denial of service. (CVE-2018-10880)

  - A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bound write in in
    fs/jbd2/transaction.c code, a denial of service, and a system crash by unmounting a crafted ext4
    filesystem image. (CVE-2018-10882)

  - A flaw was found in the Linux kernel's ext4 filesystem. A local user can cause an out-of-bounds write in
    jbd2_journal_dirty_metadata(), a denial of service, and a system crash by mounting and operating on a
    crafted ext4 filesystem image. (CVE-2018-10883)

  - A flaw was found in the Linux Kernel where an attacker may be able to have an uncontrolled read to kernel-
    memory from within a vm guest. A race condition between connect() and close() function may allow an
    attacker using the AF_VSOCK protocol to gather a 4 byte information leak or possibly intercept or corrupt
    AF_VSOCK messages destined to other clients. (CVE-2018-14625)

  - A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts
    when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while
    processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor
    address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash
    the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions before
    4.14.91 and before 4.19.13 are vulnerable. (CVE-2018-16882)

  - An issue was discovered in the proc_pid_stack function in fs/proc/base.c in the Linux kernel through
    4.18.11. It does not ensure that only root may inspect the kernel stack of an arbitrary task, allowing a
    local attacker to exploit racy stack unwinding and leak kernel task stack contents. (CVE-2018-17972)

  - Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks.
    If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of
    mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it
    has been released back to the page allocator and reused. This is fixed in the following kernel versions:
    4.9.135, 4.14.78, 4.18.16, 4.19. (CVE-2018-18281)

  - The vcpu_scan_ioapic function in arch/x86/kvm/x86.c in the Linux kernel through 4.19.2 allows local users
    to cause a denial of service (NULL pointer dereference and BUG) via crafted system calls that reach a
    situation where ioapic is uninitialized. (CVE-2018-19407)

  - In hid_debug_events_read of drivers/hid/hid-debug.c, there is a possible out of bounds write due to a
    missing bounds check. This could lead to local escalation of privilege with System execution privileges
    needed. User interaction is not needed for exploitation. Product: Android Versions: Android kernel Android
    ID: A-71361580. (CVE-2018-9516)

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-3871-4");
  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:C/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-2018-9516");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2018-16882");

  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:"2018/07/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/02/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/05");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1027-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1032-aws");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-45-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-45-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-45-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) 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 (! ('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': '4.15.0-45',
      'generic-lpae': '4.15.0-45',
      'lowlatency': '4.15.0-45',
      'gcp': '4.15.0-1027',
      'aws': '4.15.0-1032'
    }
  }
};

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-3871-4');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2018-9516', 'CVE-2018-10876', 'CVE-2018-10877', 'CVE-2018-10878', 'CVE-2018-10879', 'CVE-2018-10880', 'CVE-2018-10882', 'CVE-2018-10883', 'CVE-2018-14625', 'CVE-2018-16882', 'CVE-2018-17972', 'CVE-2018-18281', 'CVE-2018-19407');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-3871-4');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}