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nessusThis script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.ORACLELINUX_ELSA-2021-9621.NASL
HistoryDec 20, 2021 - 12:00 a.m.

Oracle Linux 7 / 8 : Unbreakable Enterprise kernel (ELSA-2021-9621)

2021-12-2000:00:00
This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
21

4.6 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:L/Au:N/C:P/I:P/A:P

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

14.2%

The remote Oracle Linux 7 / 8 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2021-9621 advisory.

  • prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel through 5.14.9 allows unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds write. (CVE-2021-41864)

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-2021-9621.
##

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

if (description)
{
  script_id(156204);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/12/20");

  script_cve_id("CVE-2021-41864");

  script_name(english:"Oracle Linux 7 / 8 : Unbreakable Enterprise kernel (ELSA-2021-9621)");

  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 / 8 host has packages installed that are affected by a vulnerability as referenced in the
ELSA-2021-9621 advisory.

  - prealloc_elems_and_freelist in kernel/bpf/stackmap.c in the Linux kernel through 5.14.9 allows
    unprivileged users to trigger an eBPF multiplication integer overflow with a resultant out-of-bounds
    write. (CVE-2021-41864)

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-2021-9621.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:P/A:P");
  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: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-2021-41864");

  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:"2021/10/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/12/20");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/12/20");

  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:"cpe:/o:oracle:linux:8");
  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-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: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) 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|8)([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 7 / 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 = ['5.4.17-2136.302.6.1.el7uek', '5.4.17-2136.302.6.1.el8uek'];
  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-2021-9621');
    }
  }
  __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 = '5.4';
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-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
    {'reference':'kernel-uek-5.4.17-2136.302.6.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
    {'reference':'kernel-uek-debug-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
    {'reference':'kernel-uek-debug-5.4.17-2136.302.6.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
    {'reference':'kernel-uek-debug-devel-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
    {'reference':'kernel-uek-debug-devel-5.4.17-2136.302.6.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
    {'reference':'kernel-uek-devel-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
    {'reference':'kernel-uek-devel-5.4.17-2136.302.6.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
    {'reference':'kernel-uek-doc-5.4.17-2136.302.6.1.el7uek', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-5.4.17'},
    {'reference':'kernel-uek-tools-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-5.4.17'},
    {'reference':'kernel-uek-tools-5.4.17-2136.302.6.1.el7uek', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-5.4.17'},
    {'reference':'kernel-uek-tools-libs-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-tools-libs-5.4.17'},
    {'reference':'perf-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python-perf-5.4.17-2136.302.6.1.el7uek', 'cpu':'aarch64', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-uek-5.4.17-2136.302.6.1.el8uek', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
    {'reference':'kernel-uek-5.4.17-2136.302.6.1.el8uek', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-5.4.17'},
    {'reference':'kernel-uek-debug-5.4.17-2136.302.6.1.el8uek', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
    {'reference':'kernel-uek-debug-5.4.17-2136.302.6.1.el8uek', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-5.4.17'},
    {'reference':'kernel-uek-debug-devel-5.4.17-2136.302.6.1.el8uek', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
    {'reference':'kernel-uek-debug-devel-5.4.17-2136.302.6.1.el8uek', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-debug-devel-5.4.17'},
    {'reference':'kernel-uek-devel-5.4.17-2136.302.6.1.el8uek', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
    {'reference':'kernel-uek-devel-5.4.17-2136.302.6.1.el8uek', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-devel-5.4.17'},
    {'reference':'kernel-uek-doc-5.4.17-2136.302.6.1.el8uek', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'exists_check':'kernel-uek-doc-5.4.17'}
];

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, 'kernel-uek / kernel-uek-debug / kernel-uek-debug-devel / etc');
}
VendorProductVersionCPE
oraclelinux7cpe:/o:oracle:linux:7
oraclelinux8cpe:/o:oracle:linux:8
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-toolsp-cpe:/a:oracle:linux:kernel-uek-tools
oraclelinuxkernel-uek-tools-libsp-cpe:/a:oracle:linux:kernel-uek-tools-libs
oraclelinuxperfp-cpe:/a:oracle:linux:perf
Rows per page:
1-10 of 111

4.6 Medium

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

PARTIAL

Integrity Impact

PARTIAL

Availability Impact

PARTIAL

AV:L/AC:L/Au:N/C:P/I:P/A:P

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

14.2%