Ubuntu 18.04 LTS : Linux kernel (AWS, GCP, KVM, OEM, Raspberry Pi 2) vulnerabilities (USN-3871-3)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3871-3. 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(121593);
  script_version("1.13");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  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:"3871-3");

  script_name(english:"Ubuntu 18.04 LTS : Linux kernel (AWS, GCP, KVM, OEM, Raspberry Pi 2) vulnerabilities (USN-3871-3)");

  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-3871-3 advisory.

    Wen Xu discovered that a use-after-free vulnerability existed in the ext4 filesystem implementation in the
    Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could
    cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10876,
    CVE-2018-10879)

    Wen Xu discovered that a buffer overflow existed in the ext4 filesystem implementation in the Linux
    kernel. An attacker could use this to construct a malicious ext4 image that, when mounted, could cause a
    denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10877)

    Wen Xu discovered that an out-of-bounds write vulnerability existed in the ext4 filesystem implementation
    in the Linux kernel. An attacker could use this to construct a malicious ext4 image that, when mounted,
    could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-10878,
    CVE-2018-10882)

    Wen Xu discovered that the ext4 filesystem implementation in the Linux kernel did not properly ensure that
    xattr information remained in inode bodies. An attacker could use this to construct a malicious ext4 image
    that, when mounted, could cause a denial of service (system crash). (CVE-2018-10880)

    Wen Xu discovered that the ext4 file system implementation in the Linux kernel could possibly perform an
    out of bounds write when updating the journal for an inline file. An attacker could use this to construct
    a malicious ext4 image that, when mounted, could cause a denial of service (system crash).
    (CVE-2018-10883)

    It was discovered that a race condition existed in the vsock address family implementation of the Linux
    kernel that could lead to a use-after-free condition. A local attacker in a guest virtual machine could
    use this to expose sensitive information (host machine kernel memory). (CVE-2018-14625)

    Cfir Cohen discovered that a use-after-free vulnerability existed in the KVM implementation of the Linux
    kernel, when handling interrupts in environments where nested virtualization is in use (nested KVM
    virtualization is not enabled by default in Ubuntu kernels). A local attacker in a guest VM could possibly
    use this to gain administrative privileges in a host machine. (CVE-2018-16882)

    Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly
    restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to
    expose sensitive information. (CVE-2018-17972)

    Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when
    completing, potentially leaving access to a physical page after it has been released to the page
    allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive
    information, or possibly execute arbitrary code. (CVE-2018-18281)

    Wei Wu discovered that the KVM implementation in the Linux kernel did not properly ensure that ioapics
    were initialized. A local attacker could use this to cause a denial of service (system crash).
    (CVE-2018-19407)

    It was discovered that the debug interface for the Linux kernel's HID subsystem did not properly perform
    bounds checking in some situations. An attacker with access to debugfs could use this to cause a denial of
    service or possibly gain additional privileges. (CVE-2018-9516)

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-3871-3");
  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-4.15.0-1029-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1031-raspi2");
  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-4.15.0-1033-oem");
  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': {
    '4.15.0': {
      'gcp': '4.15.0-1027',
      'kvm': '4.15.0-1029',
      'raspi2': '4.15.0-1031',
      'aws': '4.15.0-1032',
      'oem': '4.15.0-1033'
    }
  }
};

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-3871-3');
}

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-3871-3');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}