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nessusThis script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2020-5841.NASL
HistorySep 11, 2020 - 12:00 a.m.

Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2020-5841)

2020-09-1100:00:00
This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
48

7.6 High

AI Score

Confidence

High

The remote Oracle Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2020-5841 advisory.

  • A flaw was found in the Linux kernel’s NFS41+ subsystem. NFS41+ shares mounted in different network namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after- free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. (CVE-2018-16884)

  • An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain failure case involving TPACKET_V3, aka CID-b43d1f9f7067. (CVE-2019-20812)

  • A flaw was found in the Linux kernels implementation of the invert video code on VGA consoles when a local attacker attempts to resize the console, calling an ioctl VT_RESIZE, which causes an out-of-bounds write to occur. This flaw allows a local user with access to the VGA console to crash the system, potentially escalating their privileges on the system. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2020-14331)

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-2020-5841.
##

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

if (description)
{
  script_id(140496);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/20");

  script_cve_id("CVE-2018-16884", "CVE-2019-20812", "CVE-2020-14331");
  script_bugtraq_id(106253);

  script_name(english:"Oracle Linux 6 / 7 : Unbreakable Enterprise kernel (ELSA-2020-5841)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 6 / 7 host has packages installed that are affected by multiple vulnerabilities as referenced in
the ELSA-2020-5841 advisory.

  - A flaw was found in the Linux kernel's NFS41+ subsystem. NFS41+ shares mounted in different network
    namespaces at the same time can make bc_svc_process() use wrong back-channel IDs and cause a use-after-
    free vulnerability. Thus a malicious container user can cause a host kernel memory corruption and a system
    panic. Due to the nature of the flaw, privilege escalation cannot be fully ruled out. (CVE-2018-16884)

  - An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in
    net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain
    failure case involving TPACKET_V3, aka CID-b43d1f9f7067. (CVE-2019-20812)

  - A flaw was found in the Linux kernels implementation of the invert video code on VGA consoles when a
    local attacker attempts to resize the console, calling an ioctl VT_RESIZE, which causes an out-of-bounds
    write to occur. This flaw allows a local user with access to the VGA console to crash the system,
    potentially escalating their privileges on the system. The highest threat from this vulnerability is to
    data confidentiality and integrity as well as system availability. (CVE-2020-14331)

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-2020-5841.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:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/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-2020-14331");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2018-16884");

  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:"2018/12/18");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/09/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/09/11");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:6");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:7");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:dtrace-modules-3.8.13-118.49.1.el6uek");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:dtrace-modules-3.8.13-118.49.1.el7uek");
  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-firmware");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020-2024 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:"^(6|7)([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 6 / 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);
if ('x86_64' >!< cpu) audit(AUDIT_ARCH_NOT, 'x86_64', 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 = ['3.8.13-118.49.1.el6uek', '3.8.13-118.49.1.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-2020-5841');
    }
  }
  __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 = '3.8';
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':'dtrace-modules-3.8.13-118.49.1.el6uek-0.4.5-3.el6', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-uek-3.8.13-118.49.1.el6uek', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-3.8.13'},
    {'reference':'kernel-uek-debug-3.8.13-118.49.1.el6uek', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-3.8.13'},
    {'reference':'kernel-uek-debug-devel-3.8.13-118.49.1.el6uek', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-3.8.13'},
    {'reference':'kernel-uek-devel-3.8.13-118.49.1.el6uek', 'cpu':'x86_64', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-3.8.13'},
    {'reference':'kernel-uek-doc-3.8.13-118.49.1.el6uek', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-3.8.13'},
    {'reference':'kernel-uek-firmware-3.8.13-118.49.1.el6uek', 'release':'6', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-firmware-3.8.13'},
    {'reference':'dtrace-modules-3.8.13-118.49.1.el7uek-0.4.5-3.el7', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-uek-3.8.13-118.49.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-3.8.13'},
    {'reference':'kernel-uek-debug-3.8.13-118.49.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-3.8.13'},
    {'reference':'kernel-uek-debug-devel-3.8.13-118.49.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-3.8.13'},
    {'reference':'kernel-uek-devel-3.8.13-118.49.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-3.8.13'},
    {'reference':'kernel-uek-doc-3.8.13-118.49.1.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-3.8.13'},
    {'reference':'kernel-uek-firmware-3.8.13-118.49.1.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-firmware-3.8.13'}
];

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, 'dtrace-modules-3.8.13-118.49.1.el6uek / dtrace-modules-3.8.13-118.49.1.el7uek / kernel-uek / etc');
}
VendorProductVersionCPE
oraclelinux6cpe:/o:oracle:linux:6
oraclelinux7cpe:/o:oracle:linux:7
oraclelinuxdtrace-modules-3.8.13-118.49.1.el6uekp-cpe:/a:oracle:linux:dtrace-modules-3.8.13-118.49.1.el6uek
oraclelinuxdtrace-modules-3.8.13-118.49.1.el7uekp-cpe:/a:oracle:linux:dtrace-modules-3.8.13-118.49.1.el7uek
oraclelinuxkernel-uekp-cpe:/a:oracle:linux:kernel-uek
oraclelinuxkernel-uek-debugp-cpe:/a:oracle:linux:kernel-uek-debug
oraclelinuxkernel-uek-debug-develp-cpe:/a:oracle:linux:kernel-uek-debug-devel
oraclelinuxkernel-uek-develp-cpe:/a:oracle:linux:kernel-uek-devel
oraclelinuxkernel-uek-docp-cpe:/a:oracle:linux:kernel-uek-doc
oraclelinuxkernel-uek-firmwarep-cpe:/a:oracle:linux:kernel-uek-firmware