Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-3931-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3931-1. 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(123678);
  script_version("1.12");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/08/27");

  script_cve_id(
    "CVE-2018-14678",
    "CVE-2018-18021",
    "CVE-2018-19824",
    "CVE-2019-3459",
    "CVE-2019-3460",
    "CVE-2019-6974",
    "CVE-2019-7221",
    "CVE-2019-7222",
    "CVE-2019-7308",
    "CVE-2019-8912",
    "CVE-2019-8980",
    "CVE-2019-9213"
  );
  script_xref(name:"USN", value:"3931-1");

  script_name(english:"Ubuntu 18.04 LTS : Linux kernel vulnerabilities (USN-3931-1)");

  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-3931-1 advisory.

    M. Vefa Bicakci and Andy Lutomirski discovered that the kernel did not properly set up all arguments to an
    error handler callback used when running as a paravirtualized guest. An unprivileged attacker in a
    paravirtualized guest VM could use this to cause a denial of service (guest VM crash). (CVE-2018-14678)

    It was discovered that the KVM implementation in the Linux kernel on ARM 64bit processors did not properly
    handle some ioctls. An attacker with the privilege to create KVM-based virtual machines could use this to
    cause a denial of service (host system crash) or execute arbitrary code in the host. (CVE-2018-18021)

    Mathias Payer and Hui Peng discovered a use-after-free vulnerability in the Advanced Linux Sound
    Architecture (ALSA) subsystem. A physically proximate attacker could use this to cause a denial of service
    (system crash). (CVE-2018-19824)

    Shlomi Oberman, Yuli Shapiro, and Ran Menscher discovered an information leak in the Bluetooth
    implementation of the Linux kernel. An attacker within Bluetooth range could use this to expose sensitive
    information (kernel memory). (CVE-2019-3459, CVE-2019-3460)

    Jann Horn discovered that the KVM implementation in the Linux kernel contained a use-after-free
    vulnerability. An attacker in a guest VM with access to /dev/kvm could use this to cause a denial of
    service (guest VM crash). (CVE-2019-6974)

    Jim Mattson and Felix Wilhelm discovered a use-after-free vulnerability in the KVM subsystem of the Linux
    kernel, when using nested virtual machines. A local attacker in a guest VM could use this to cause a
    denial of service (system crash) or possibly execute arbitrary code in the host system. (CVE-2019-7221)

    Felix Wilhelm discovered that an information leak vulnerability existed in the KVM subsystem of the Linux
    kernel, when nested virtualization is used. A local attacker could use this to expose sensitive
    information (host system memory to a guest VM). (CVE-2019-7222)

    Jann Horn discovered that the eBPF implementation in the Linux kernel was insufficiently hardened against
    Spectre V1 attacks. A local attacker could use this to expose sensitive information. (CVE-2019-7308)

    It was discovered that a use-after-free vulnerability existed in the user- space API for crypto (af_alg)
    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-2019-8912)

    It was discovered that the Linux kernel did not properly deallocate memory when handling certain errors
    while reading files. A local attacker could use this to cause a denial of service (excessive memory
    consumption). (CVE-2019-8980)

    Jann Horn discovered that the mmap implementation in the Linux kernel did not properly check for the mmap
    minimum address in some situations. A local attacker could use this to assist exploiting a kernel NULL
    pointer dereference vulnerability. (CVE-2019-9213)

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-3931-1");
  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:F/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:F/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-8912");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2019-6974");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");
  script_set_attribute(attribute:"metasploit_name", value:'Reliable Datagram Sockets (RDS) rds_atomic_free_op NULL pointer dereference Privilege Escalation');
  script_set_attribute(attribute:"exploit_framework_metasploit", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/07/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/04/02");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/04/03");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1010-oracle");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1029-gcp");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1031-kvm");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1033-raspi2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-1035-oem");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-47-generic");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-47-generic-lpae");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-47-lowlatency");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:linux-image-4.15.0-47-snapdragon");
  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': {
      'generic': '4.15.0-47',
      'generic-lpae': '4.15.0-47',
      'lowlatency': '4.15.0-47',
      'snapdragon': '4.15.0-47',
      'oracle': '4.15.0-1010',
      'gcp': '4.15.0-1029',
      'kvm': '4.15.0-1031',
      'raspi2': '4.15.0-1033',
      'oem': '4.15.0-1035'
    }
  }
};

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-3931-1');
}

if (get_one_kb_item('Host/ksplice/kernel-cves'))
{
  var cve_list = make_list('CVE-2018-14678', 'CVE-2018-18021', 'CVE-2018-19824', 'CVE-2019-3459', 'CVE-2019-3460', 'CVE-2019-6974', 'CVE-2019-7221', 'CVE-2019-7222', 'CVE-2019-7308', 'CVE-2019-8912', 'CVE-2019-8980', 'CVE-2019-9213');
  if (ksplice_cves_check(cve_list))
  {
    audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for USN-3931-1');
  }
  else
  {
    extra = extra + ksplice_reporting_text();
  }
}
if (extra) {
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : extra
  );
  exit(0);
}