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nessusThis script is Copyright (C) 2020-2021 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2020-2102.NASL
HistoryMay 15, 2020 - 12:00 a.m.

Oracle Linux 8 : kernel (ELSA-2020-2102)

2020-05-1500:00:00
This script is Copyright (C) 2020-2021 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
100

The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2020-2102 advisory.

  • A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest when nested virtualisation is enabled. Under some circumstances, an L2 guest may trick the L0 guest into accessing sensitive L1 resources that should be inaccessible to the L2 guest. (CVE-2020-2732)

  • A NULL pointer dereference flaw was found in the Linux kernel’s SELinux subsystem in versions before 5.7.
    This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol’s category bitmap into the SELinux extensible bitmap via the’ ebitmap_netlbl_import’ routine. While processing the CIPSO restricted bitmap tag in the ‘cipso_v4_parsetag_rbm’ routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network user to crash the system kernel, resulting in a denial of service. (CVE-2020-10711)

  • In the Linux kernel 4.19 through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur. (CVE-2020-11884)

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-2020-2102.
##

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

if (description)
{
  script_id(136646);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/09/08");

  script_cve_id("CVE-2020-2732", "CVE-2020-10711", "CVE-2020-11884");
  script_xref(name:"RHSA", value:"2020:2102");

  script_name(english:"Oracle Linux 8 : kernel (ELSA-2020-2102)");

  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 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2020-2102 advisory.

  - A flaw was discovered in the way that the KVM hypervisor handled instruction emulation for an L2 guest
    when nested virtualisation is enabled. Under some circumstances, an L2 guest may trick the L0 guest into
    accessing sensitive L1 resources that should be inaccessible to the L2 guest. (CVE-2020-2732)

  - A NULL pointer dereference flaw was found in the Linux kernel's SELinux subsystem in versions before 5.7.
    This flaw occurs while importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into
    the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO
    restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate
    that the category bitmap is present, even if it has not been allocated. This issue leads to a NULL pointer
    dereference issue while importing the same category bitmap into SELinux. This flaw allows a remote network
    user to crash the system kernel, resulting in a denial of service. (CVE-2020-10711)

  - In the Linux kernel 4.19 through 5.6.7 on the s390 platform, code execution may occur because of a race
    condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect
    against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur. (CVE-2020-11884)

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-2020-2102.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/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:H/PR:L/UI:N/S:U/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-2020-11884");

  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:"2020/02/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/15");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:oracle:linux:8");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:bpftool");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-abi-whitelists");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-cross-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug-core");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-debug-modules-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-headers");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-modules-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-tools-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:oracle:linux:kernel-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:python3-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) 2020-2021 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:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 8', '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 = ['4.18.0-193.1.2.el8_2'];
  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-2020-2102');
    }
  }
  __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 = '4.18';
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':'bpftool-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-4.18.0'},
    {'reference':'kernel-abi-whitelists-4.18.0-193.1.2.el8_2', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-abi-whitelists-4.18.0'},
    {'reference':'kernel-core-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-core-4.18.0'},
    {'reference':'kernel-cross-headers-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-cross-headers-4.18.0'},
    {'reference':'kernel-cross-headers-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-cross-headers-4.18.0'},
    {'reference':'kernel-debug-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-4.18.0'},
    {'reference':'kernel-debug-core-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-core-4.18.0'},
    {'reference':'kernel-debug-devel-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-devel-4.18.0'},
    {'reference':'kernel-debug-modules-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-modules-4.18.0'},
    {'reference':'kernel-debug-modules-extra-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-debug-modules-extra-4.18.0'},
    {'reference':'kernel-devel-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-devel-4.18.0'},
    {'reference':'kernel-headers-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-headers-4.18.0'},
    {'reference':'kernel-headers-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-headers-4.18.0'},
    {'reference':'kernel-modules-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-modules-4.18.0'},
    {'reference':'kernel-modules-extra-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-modules-extra-4.18.0'},
    {'reference':'kernel-tools-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-4.18.0'},
    {'reference':'kernel-tools-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-4.18.0'},
    {'reference':'kernel-tools-libs-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-4.18.0'},
    {'reference':'kernel-tools-libs-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-4.18.0'},
    {'reference':'kernel-tools-libs-devel-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-devel-4.18.0'},
    {'reference':'kernel-tools-libs-devel-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-tools-libs-devel-4.18.0'},
    {'reference':'perf-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'perf-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-4.18.0-193.1.2.el8_2', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-4.18.0-193.1.2.el8_2', 'cpu':'x86_64', 'release':'8', '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_WARNING,
      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, 'bpftool / kernel / kernel-abi-whitelists / etc');
}
VendorProductVersionCPE
oraclelinuxkernelp-cpe:/a:oracle:linux:kernel
oraclelinuxkernel-abi-whitelistsp-cpe:/a:oracle:linux:kernel-abi-whitelists
oraclelinuxkernel-corep-cpe:/a:oracle:linux:kernel-core
oraclelinuxkernel-cross-headersp-cpe:/a:oracle:linux:kernel-cross-headers
oraclelinuxkernel-debugp-cpe:/a:oracle:linux:kernel-debug
oraclelinuxkernel-debug-corep-cpe:/a:oracle:linux:kernel-debug-core
oraclelinuxkernel-debug-develp-cpe:/a:oracle:linux:kernel-debug-devel
oraclelinuxkernel-debug-modulesp-cpe:/a:oracle:linux:kernel-debug-modules
oraclelinuxkernel-debug-modules-extrap-cpe:/a:oracle:linux:kernel-debug-modules-extra
oraclelinuxkernel-develp-cpe:/a:oracle:linux:kernel-devel
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