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nessusThis script is Copyright (C) 2019-2021 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2019-4799.NASL
HistorySep 23, 2019 - 12:00 a.m.

Oracle Linux 7 : Unbreakable Enterprise kernel (ELSA-2019-4799)

2019-09-2300:00:00
This script is Copyright (C) 2019-2021 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
32

The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2019-4799 advisory.

  • An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux kernel’s KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer ‘struct kvm_coalesced_mmio’ object, wherein write indices ‘ring->first’ and ‘ring->last’ value could be supplied by a host user-space process. An unprivileged host user or process with access to ‘/dev/kvm’ device could use this flaw to crash the host kernel, resulting in a denial of service or potentially escalating privileges on the system. (CVE-2019-14821)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2019-4799.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(129140);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/08");

  script_cve_id("CVE-2019-14821");

  script_name(english:"Oracle Linux 7 : Unbreakable Enterprise kernel (ELSA-2019-4799)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the
ELSA-2019-4799 advisory.

  - An out-of-bounds access issue was found in the Linux kernel, all versions through 5.3, in the way Linux
    kernel's KVM hypervisor implements the Coalesced MMIO write operation. It operates on an MMIO ring buffer
    'struct kvm_coalesced_mmio' object, wherein write indices 'ring->first' and 'ring->last' value could be
    supplied by a host user-space process. An unprivileged host user or process with access to '/dev/kvm'
    device could use this flaw to crash the host kernel, resulting in a denial of service or potentially
    escalating privileges on the system. (CVE-2019-14821)

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://linux.oracle.com/errata/ELSA-2019-4799.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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:C/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-2019-14821");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/09/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/09/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/09/23");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-doc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-uek-tools-libs-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:perf");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:python-perf");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Oracle Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 2019-2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("linux_alt_patch_detect.nasl", "ssh_get_info.nasl");
  script_require_keys("Host/OracleLinux", "Host/RedHat/release", "Host/RedHat/rpm-list", "Host/local_checks_enabled");

  exit(0);
}


include('audit.inc');
include('global_settings.inc');
include('ksplice.inc');
include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^7([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7', 'Oracle Linux ' + os_ver);

if (!get_kb_item('Host/RedHat/rpm-list')) 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var machine_uptrack_level = get_one_kb_item('Host/uptrack-uname-r');
if (machine_uptrack_level)
{
  var trimmed_uptrack_level = ereg_replace(string:machine_uptrack_level, pattern:"\.(x86_64|i[3-6]86|aarch64)$", replace:'');
  var fixed_uptrack_levels = ['4.14.35-1902.5.2.2.el7uek'];
  foreach var fixed_uptrack_level ( fixed_uptrack_levels ) {
    if (rpm_spec_vers_cmp(a:trimmed_uptrack_level, b:fixed_uptrack_level) >= 0)
    {
      audit(AUDIT_PATCH_INSTALLED, 'KSplice hotfix for ELSA-2019-4799');
    }
  }
  __rpm_report = 'Running KSplice level of ' + trimmed_uptrack_level + ' does not meet the minimum fixed level of ' + join(fixed_uptrack_levels, sep:' / ') + ' for this advisory.\n\n';
}

var kernel_major_minor = get_kb_item('Host/uname/major_minor');
if (empty_or_null(kernel_major_minor)) exit(1, 'Unable to determine kernel major-minor level.');
var expected_kernel_major_minor = '4.14';
if (kernel_major_minor != expected_kernel_major_minor)
  audit(AUDIT_OS_NOT, 'running kernel level ' + expected_kernel_major_minor + ', it is running kernel level ' + kernel_major_minor);

var pkgs = [
    {'reference':'kernel-uek-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
    {'reference':'kernel-uek-4.14.35-1902.5.2.2.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-4.14.35'},
    {'reference':'kernel-uek-debug-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
    {'reference':'kernel-uek-debug-4.14.35-1902.5.2.2.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-4.14.35'},
    {'reference':'kernel-uek-debug-devel-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
    {'reference':'kernel-uek-debug-devel-4.14.35-1902.5.2.2.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-4.14.35'},
    {'reference':'kernel-uek-devel-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
    {'reference':'kernel-uek-devel-4.14.35-1902.5.2.2.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-4.14.35'},
    {'reference':'kernel-uek-doc-4.14.35-1902.5.2.2.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-4.14.35'},
    {'reference':'kernel-uek-headers-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-headers-4.14.35'},
    {'reference':'kernel-uek-tools-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
    {'reference':'kernel-uek-tools-4.14.35-1902.5.2.2.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-4.14.35'},
    {'reference':'kernel-uek-tools-libs-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-4.14.35'},
    {'reference':'kernel-uek-tools-libs-devel-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-devel-4.14.35'},
    {'reference':'perf-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-4.14.35-1902.5.2.2.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE}
];

var flag = 0;
foreach var package_array ( pkgs ) {
  var reference = NULL;
  var release = NULL;
  var sp = NULL;
  var cpu = NULL;
  var el_string = NULL;
  var rpm_spec_vers_cmp = NULL;
  var epoch = NULL;
  var allowmaj = NULL;
  var exists_check = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = 'EL' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && release) {
    if (exists_check) {
        if (rpm_exists(release:release, rpm:exists_check) && rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
    } else {
        if (rpm_check(release:release, sp:sp, cpu:cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj)) flag++;
    }
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'kernel-uek / kernel-uek-debug / kernel-uek-debug-devel / etc');
}
Related for ORACLELINUX_ELSA-2019-4799.NASL